feat(web): view transitions from timeline to viewer

Change-Id: I0a37b417ee4c247dcc93d442c976eede6a6a6964

e2e/src/ui/specs/search/search-gallery.e2e-spec.ts

@@ -6,6 +6,7 @@ import {
   generateTimelineData,
   TimelineAssetConfig,
   TimelineData,
+  toAssetResponseDto,
 } from 'src/ui/generators/timeline';
 import { setupBaseMockApiRoutes } from 'src/ui/mock-network/base-network';
 import { setupTimelineMockApiRoutes, TimelineTestContext } from 'src/ui/mock-network/timeline-network';
@@ -30,6 +31,10 @@ test.describe('search gallery-viewer', () => {
   };
 
   test.beforeAll(async () => {
+    test.fail(
+      process.env.PW_EXPERIMENTAL_SERVICE_WORKER_NETWORK_EVENTS !== '1',
+      'This test requires env var: PW_EXPERIMENTAL_SERVICE_WORKER_NETWORK_EVENTS=1',
+    );
     adminUserId = faker.string.uuid();
     testContext.adminId = adminUserId;
     timelineRestData = generateTimelineData({ ...createDefaultTimelineConfig(), ownerId: adminUserId });
@@ -44,7 +49,10 @@ test.describe('search gallery-viewer', () => {
 
     await context.route('**/api/search/metadata', async (route, request) => {
       if (request.method() === 'POST') {
-        const searchAssets = assets.slice(0, 5).filter((asset) => !changes.assetDeletions.includes(asset.id));
+        const searchAssets = assets
+          .slice(0, 5)
+          .filter((asset) => !changes.assetDeletions.includes(asset.id))
+          .map((asset) => toAssetResponseDto(asset));
         return route.fulfill({
           status: 200,
           contentType: 'application/json',

e2e/src/ui/specs/timeline/utils.ts

@@ -143,7 +143,7 @@ export const timelineUtils = {
     return page.locator('#asset-grid');
   },
   async waitForTimelineLoad(page: Page) {
-    await expect(timelineUtils.locator(page)).toBeInViewport();
+    await page.locator('#asset-grid[data-initialized]').waitFor();
     await expect.poll(() => thumbnailUtils.locator(page).count()).toBeGreaterThan(0);
   },
   async getScrollTop(page: Page) {
@@ -163,14 +163,17 @@ export const assetViewerUtils = {
     return page.locator('#immich-asset-viewer');
   },
   async waitForViewerLoad(page: Page, asset: TimelineAssetConfig) {
-    await page
+    const imgLocator = page.locator(`[data-viewer-content] img[data-testid="preview"][src*="${asset.id}"]`);
-      .locator(
+    const videoLocator = page.locator(`[data-viewer-content] video[poster*="${asset.id}"]`);
-        `img[draggable="false"][src="/api/assets/${asset.id}/thumbnail?size=preview&c=${asset.thumbhash}&edited=true"]`,
+    await imgLocator.or(videoLocator).waitFor();
-      )
+
-      .or(
+    if ((await videoLocator.count()) === 0) {
-        page.locator(`video[poster="/api/assets/${asset.id}/thumbnail?size=preview&c=${asset.thumbhash}&edited=true"]`),
+      await expect
-      )
+        .poll(() => imgLocator.evaluate((img: HTMLImageElement) => img.complete && img.naturalWidth > 0))
-      .waitFor();
+        .toBe(true);
+    }
+
+    await expect(page.locator('#immich-asset-viewer')).not.toHaveAttribute('data-navigating');
   },
   async expectActiveAssetToBe(page: Page, assetId: string) {
     const activeElement = () =>

e2e/src/web/specs/asset-viewer/asset-viewer.ui-spec.ts

@@ -0,0 +1,273 @@
+import { faker } from '@faker-js/faker';
+import { expect, test } from '@playwright/test';
+import {
+  Changes,
+  createDefaultTimelineConfig,
+  generateTimelineData,
+  SeededRandom,
+  selectRandom,
+  TimelineAssetConfig,
+  TimelineData,
+} from 'src/ui/generators/timeline';
+import { setupBaseMockApiRoutes } from 'src/ui/mock-network/base-network';
+import { setupTimelineMockApiRoutes, TimelineTestContext } from 'src/ui/mock-network/timeline-network';
+import { assetViewerUtils } from 'src/ui/specs/timeline/utils';
+import { utils } from 'src/utils';
+
+test.describe.configure({ mode: 'parallel' });
+test.describe('asset-viewer', () => {
+  const rng = new SeededRandom(529);
+  let adminUserId: string;
+  let timelineRestData: TimelineData;
+  const assets: TimelineAssetConfig[] = [];
+  const yearMonths: string[] = [];
+  const testContext = new TimelineTestContext();
+  const changes: Changes = {
+    albumAdditions: [],
+    assetDeletions: [],
+    assetArchivals: [],
+    assetFavorites: [],
+  };
+
+  test.beforeAll(async () => {
+    utils.initSdk();
+    adminUserId = faker.string.uuid();
+    testContext.adminId = adminUserId;
+    timelineRestData = generateTimelineData({ ...createDefaultTimelineConfig(), ownerId: adminUserId });
+    for (const timeBucket of timelineRestData.buckets.values()) {
+      assets.push(...timeBucket);
+    }
+    for (const yearMonth of timelineRestData.buckets.keys()) {
+      const [year, month] = yearMonth.split('-');
+      yearMonths.push(`${year}-${Number(month)}`);
+    }
+  });
+
+  test.beforeEach(async ({ context }) => {
+    await setupBaseMockApiRoutes(context, adminUserId);
+    await setupTimelineMockApiRoutes(context, timelineRestData, changes, testContext);
+  });
+
+  test.afterEach(() => {
+    testContext.slowBucket = false;
+    changes.albumAdditions = [];
+    changes.assetDeletions = [];
+    changes.assetArchivals = [];
+    changes.assetFavorites = [];
+  });
+
+  test.describe('/photos/:id', () => {
+    test('Navigate to next asset via button', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${asset.id}`);
+
+      await page.getByLabel('View next asset').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 1]);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${assets[index + 1].id}`);
+    });
+
+    test('Navigate to previous asset via button', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${asset.id}`);
+
+      await page.getByLabel('View previous asset').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index - 1]);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${assets[index - 1].id}`);
+    });
+
+    test('Navigate to next asset via keyboard (ArrowRight)', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${asset.id}`);
+
+      await page.getByTestId('next-asset').waitFor();
+      await page.keyboard.press('ArrowRight');
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 1]);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${assets[index + 1].id}`);
+    });
+
+    test('Navigate to previous asset via keyboard (ArrowLeft)', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${asset.id}`);
+
+      await page.getByTestId('previous-asset').waitFor();
+      await page.keyboard.press('ArrowLeft');
+      await assetViewerUtils.waitForViewerLoad(page, assets[index - 1]);
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${assets[index - 1].id}`);
+    });
+
+    test('Navigate forward 5 times via button', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+
+      for (let i = 1; i <= 5; i++) {
+        await page.getByLabel('View next asset').click();
+        await assetViewerUtils.waitForViewerLoad(page, assets[index + i]);
+        await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${assets[index + i].id}`);
+      }
+    });
+
+    test('Navigate backward 5 times via button', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+
+      for (let i = 1; i <= 5; i++) {
+        await page.getByLabel('View previous asset').click();
+        await assetViewerUtils.waitForViewerLoad(page, assets[index - i]);
+        await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${assets[index - i].id}`);
+      }
+    });
+
+    test('Navigate forward then backward via keyboard', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+
+      // Navigate forward 3 times
+      for (let i = 1; i <= 3; i++) {
+        await page.getByTestId('next-asset').waitFor();
+        await page.keyboard.press('ArrowRight');
+        await assetViewerUtils.waitForViewerLoad(page, assets[index + i]);
+      }
+
+      // Navigate backward 3 times to return to original
+      for (let i = 2; i >= 0; i--) {
+        await page.getByTestId('previous-asset').waitFor();
+        await page.keyboard.press('ArrowLeft');
+        await assetViewerUtils.waitForViewerLoad(page, assets[index + i]);
+      }
+
+      // Verify we're back at the original asset
+      await expect.poll(() => new URL(page.url()).pathname).toBe(`/photos/${asset.id}`);
+    });
+
+    test('Verify no next button on last asset', async ({ page }) => {
+      const lastAsset = assets.at(-1)!;
+      await page.goto(`/photos/${lastAsset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, lastAsset);
+
+      // Verify next button doesn't exist
+      await expect(page.getByLabel('View next asset')).toHaveCount(0);
+    });
+
+    test('Verify no previous button on first asset', async ({ page }) => {
+      const firstAsset = assets[0];
+      await page.goto(`/photos/${firstAsset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, firstAsset);
+
+      // Verify previous button doesn't exist
+      await expect(page.getByLabel('View previous asset')).toHaveCount(0);
+    });
+
+    test('Delete photo advances to next', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await page.getByLabel('Delete').click();
+      const index = assets.indexOf(asset);
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 1]);
+    });
+    test('Delete photo advances to next (2x)', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await page.getByLabel('Delete').click();
+      const index = assets.indexOf(asset);
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 1]);
+      await page.getByLabel('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 2]);
+    });
+    test('Delete last photo advances to prev', async ({ page }) => {
+      const asset = assets.at(-1)!;
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await page.getByLabel('Delete').click();
+      const index = assets.indexOf(asset);
+      await assetViewerUtils.waitForViewerLoad(page, assets[index - 1]);
+    });
+    test('Delete last photo advances to prev (2x)', async ({ page }) => {
+      const asset = assets.at(-1)!;
+      await page.goto(`/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await page.getByLabel('Delete').click();
+      const index = assets.indexOf(asset);
+      await assetViewerUtils.waitForViewerLoad(page, assets[index - 1]);
+      await page.getByLabel('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index - 2]);
+    });
+  });
+  test.describe('/trash/photos/:id', () => {
+    test('Delete trashed photo advances to next', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      const deletedAssets = assets.slice(index - 10, index + 10).map((asset) => asset.id);
+      changes.assetDeletions.push(...deletedAssets);
+      await page.goto(`/trash/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await page.getByLabel('Delete').click();
+      // confirm dialog
+      await page.getByRole('button').getByText('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 1]);
+    });
+    test('Delete trashed photo advances to next 2x', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      const deletedAssets = assets.slice(index - 10, index + 10).map((asset) => asset.id);
+      changes.assetDeletions.push(...deletedAssets);
+      await page.goto(`/trash/photos/${asset.id}`);
+      await assetViewerUtils.waitForViewerLoad(page, asset);
+      await page.getByLabel('Delete').click();
+      // confirm dialog
+      await page.getByRole('button').getByText('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 1]);
+      await page.getByLabel('Delete').click();
+      // confirm dialog
+      await page.getByRole('button').getByText('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 2]);
+    });
+    test('Delete trashed photo advances to prev', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      const deletedAssets = assets.slice(index - 10, index + 10).map((asset) => asset.id);
+      changes.assetDeletions.push(...deletedAssets);
+      await page.goto(`/trash/photos/${assets[index + 9].id}`);
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 9]);
+      await page.getByLabel('Delete').click();
+      // confirm dialog
+      await page.getByRole('button').getByText('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 8]);
+    });
+    test('Delete trashed photo advances to prev 2x', async ({ page }) => {
+      const asset = selectRandom(assets, rng);
+      const index = assets.indexOf(asset);
+      const deletedAssets = assets.slice(index - 10, index + 10).map((asset) => asset.id);
+      changes.assetDeletions.push(...deletedAssets);
+      await page.goto(`/trash/photos/${assets[index + 9].id}`);
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 9]);
+      await page.getByLabel('Delete').click();
+      // confirm dialog
+      await page.getByRole('button').getByText('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 8]);
+      await page.getByLabel('Delete').click();
+      // confirm dialog
+      await page.getByRole('button').getByText('Delete').click();
+      await assetViewerUtils.waitForViewerLoad(page, assets[index + 7]);
+    });
+  });
+});

web/src/app.css

@@ -75,6 +75,35 @@
     --immich-dark-bg: 10 10 10;
     --immich-dark-fg: 229 231 235;
     --immich-dark-gray: 33 33 33;
+
+    /* transitions */
+    --immich-split-viewer-nav: enabled;
+
+    /* view transition variables */
+    /* Base animation duration for standard transitions (page fades, info panel) */
+    --vt-duration-default: 250ms;
+    /* Duration for hero transitions (thumbnail to full viewer) */
+    --vt-duration-hero: 280ms;
+    /* Duration for next/previous photo navigation */
+    --vt-duration-viewer-navigation: 270ms;
+    /* Duration for slideshow mode transitions */
+    --vt-duration-slideshow: 1s;
+    /* Easing function for slide animations (ease-out) */
+    --vt-viewer-slide-easing: cubic-bezier(0.2, 0, 0, 1);
+    /* How far images slide in/out during navigation (% of viewport) */
+    --vt-viewer-slide-distance: 15%;
+    /* Starting opacity for fly transitions (slide+fade effect) */
+    --vt-viewer-opacity-start: 0.1;
+    /* Maximum blur during fly transitions (currently disabled) */
+    --vt-viewer-blur-max: 0px;
+
+    --vt-viewer-next-in: flyInRight;
+    --vt-viewer-next-out: flyOutLeft;
+    --vt-viewer-prev-in: flyInLeft;
+    --vt-viewer-prev-out: flyOutRight;
+    --vt-viewer-old-opacity: 1;
+    /* Easing function for memory and hero morph transitions */
+    --vt-memory-easing: cubic-bezier(0.2, 0, 0, 1);
   }
 
   button:not(:disabled),
@@ -176,3 +205,370 @@
     @apply bg-subtle rounded-lg;
   }
 }
+
+@layer base {
+  ::view-transition {
+    background: var(--color-black);
+    animation-duration: var(--vt-duration-default);
+  }
+
+  ::view-transition-old(*),
+  ::view-transition-new(*) {
+    mix-blend-mode: normal;
+    animation-duration: inherit;
+  }
+
+  ::view-transition-old(*) {
+    animation-name: fadeOut;
+    animation-fill-mode: forwards;
+  }
+  ::view-transition-new(*) {
+    animation-name: fadeIn;
+    animation-fill-mode: forwards;
+  }
+
+  ::view-transition-old(root) {
+    animation: var(--vt-duration-default) 0s fadeOut forwards;
+  }
+  ::view-transition-new(root) {
+    animation: var(--vt-duration-default) 0s fadeIn forwards;
+  }
+  html:active-view-transition-type(slideshow) {
+    &::view-transition-old(*) {
+      animation: var(--vt-duration-slideshow) linear crossfadeOut forwards;
+    }
+    &::view-transition-new(*) {
+      animation: var(--vt-duration-slideshow) linear crossfadeIn forwards;
+    }
+    &::view-transition-image-pair(*) {
+      isolation: auto;
+    }
+  }
+  html:active-view-transition-type(viewer-nav) {
+    &::view-transition-old(root) {
+      animation: var(--vt-duration-hero) 0s fadeOut forwards;
+    }
+    &::view-transition-new(root) {
+      animation: var(--vt-duration-hero) 0s fadeIn forwards;
+    }
+  }
+  ::view-transition-image-pair(info) {
+    isolation: auto;
+  }
+  ::view-transition-old(info) {
+    animation: var(--vt-duration-default) 0s panelSlideOutRight forwards;
+  }
+  ::view-transition-new(info) {
+    animation: var(--vt-duration-default) 0s panelSlideInRight forwards;
+  }
+
+  ::view-transition-group(detail-panel) {
+    z-index: 1;
+  }
+  ::view-transition-old(detail-panel),
+  ::view-transition-new(detail-panel) {
+    animation: none;
+  }
+  ::view-transition-group(letterbox-left),
+  ::view-transition-group(letterbox-right),
+  ::view-transition-group(letterbox-top),
+  ::view-transition-group(letterbox-bottom) {
+    animation-duration: var(--vt-duration-viewer-navigation);
+    animation-timing-function: var(--vt-viewer-slide-easing);
+    z-index: 4;
+  }
+
+  ::view-transition-image-pair(letterbox-left),
+  ::view-transition-image-pair(letterbox-right),
+  ::view-transition-image-pair(letterbox-top),
+  ::view-transition-image-pair(letterbox-bottom) {
+    isolation: auto;
+  }
+
+  ::view-transition-old(letterbox-left),
+  ::view-transition-old(letterbox-right),
+  ::view-transition-old(letterbox-top),
+  ::view-transition-old(letterbox-bottom),
+  ::view-transition-new(letterbox-left),
+  ::view-transition-new(letterbox-right),
+  ::view-transition-new(letterbox-top),
+  ::view-transition-new(letterbox-bottom) {
+    animation: none;
+    width: 100%;
+    height: 100%;
+    object-fit: fill;
+    background-color: var(--color-black);
+  }
+
+  ::view-transition-group(exclude-leftbutton),
+  ::view-transition-group(exclude-rightbutton),
+  ::view-transition-group(exclude) {
+    animation: none;
+    z-index: 5;
+  }
+  ::view-transition-old(exclude-leftbutton),
+  ::view-transition-old(exclude-rightbutton),
+  ::view-transition-old(exclude) {
+    visibility: hidden;
+  }
+  ::view-transition-new(exclude-leftbutton),
+  ::view-transition-new(exclude-rightbutton),
+  ::view-transition-new(exclude) {
+    animation: none;
+    z-index: 5;
+  }
+
+  ::view-transition-group(hero) {
+    animation-duration: var(--vt-duration-hero);
+    animation-timing-function: var(--vt-memory-easing);
+  }
+  ::view-transition-old(hero) {
+    animation: none;
+    display: none;
+  }
+  ::view-transition-new(hero) {
+    animation: none;
+    align-content: center;
+  }
+  ::view-transition-old(next),
+  ::view-transition-old(next-old),
+  ::view-transition-new(next),
+  ::view-transition-new(next-new),
+  ::view-transition-old(previous),
+  ::view-transition-old(previous-old),
+  ::view-transition-new(previous),
+  ::view-transition-new(previous-new) {
+    animation-duration: var(--vt-duration-viewer-navigation);
+    animation-timing-function: var(--vt-viewer-slide-easing);
+    animation-fill-mode: forwards;
+  }
+
+  ::view-transition-old(next),
+  ::view-transition-old(next-old),
+  ::view-transition-old(previous),
+  ::view-transition-old(previous-old) {
+    opacity: var(--vt-viewer-old-opacity);
+  }
+
+  ::view-transition-old(next),
+  ::view-transition-old(next-old) {
+    animation-name: var(--vt-viewer-next-out);
+  }
+
+  ::view-transition-new(next),
+  ::view-transition-new(next-new) {
+    animation-name: var(--vt-viewer-next-in);
+  }
+
+  ::view-transition-old(previous),
+  ::view-transition-old(previous-old) {
+    animation-name: var(--vt-viewer-prev-out);
+  }
+
+  ::view-transition-new(previous),
+  ::view-transition-new(previous-new) {
+    animation-name: var(--vt-viewer-prev-in);
+  }
+
+  ::view-transition-old(next-old),
+  ::view-transition-new(next-new),
+  ::view-transition-old(previous-old),
+  ::view-transition-new(previous-new) {
+    overflow: hidden;
+  }
+
+  ::view-transition-old(previous-old) {
+    z-index: -1;
+  }
+
+  @keyframes flyInLeft {
+    from {
+      transform: translateX(calc(-1 * var(--vt-viewer-slide-distance)));
+      opacity: var(--vt-viewer-opacity-start);
+      filter: blur(var(--vt-viewer-blur-max));
+    }
+    to {
+      opacity: 1;
+      filter: blur(0);
+    }
+  }
+
+  @keyframes flyOutLeft {
+    from {
+      opacity: 1;
+      filter: blur(0);
+    }
+    to {
+      transform: translateX(calc(-1 * var(--vt-viewer-slide-distance)));
+      opacity: var(--vt-viewer-opacity-start);
+      filter: blur(var(--vt-viewer-blur-max));
+    }
+  }
+
+  @keyframes flyInRight {
+    from {
+      transform: translateX(var(--vt-viewer-slide-distance));
+      opacity: var(--vt-viewer-opacity-start);
+      filter: blur(var(--vt-viewer-blur-max));
+    }
+    to {
+      opacity: 1;
+      filter: blur(0);
+    }
+  }
+
+  @keyframes flyOutRight {
+    from {
+      opacity: 1;
+      filter: blur(0);
+    }
+    to {
+      transform: translateX(var(--vt-viewer-slide-distance));
+      opacity: var(--vt-viewer-opacity-start);
+      filter: blur(var(--vt-viewer-blur-max));
+    }
+  }
+
+  @keyframes panelSlideInRight {
+    from {
+      transform: translateX(100%);
+    }
+    to {
+      transform: translateX(0);
+    }
+  }
+
+  @keyframes panelSlideOutRight {
+    from {
+      transform: translateX(0);
+    }
+    to {
+      transform: translateX(100%);
+    }
+  }
+
+  /* cubic fade curves so combined opacity stays close to 1.0 during crossfade */
+  @keyframes fadeIn {
+    from {
+      opacity: 0;
+    }
+    50% {
+      opacity: 0.85;
+    }
+    to {
+      opacity: 1;
+    }
+  }
+  @keyframes fadeOut {
+    from {
+      opacity: 1;
+    }
+    50% {
+      opacity: 0.85;
+    }
+    to {
+      opacity: 0;
+    }
+  }
+
+  @keyframes crossfadeIn {
+    from {
+      opacity: 0;
+    }
+    to {
+      opacity: 1;
+    }
+  }
+  @keyframes crossfadeOut {
+    from {
+      opacity: 1;
+    }
+    to {
+      opacity: 0;
+    }
+  }
+
+  @media (prefers-reduced-motion: reduce) {
+    ::view-transition-group(hero) {
+      animation-name: none;
+    }
+
+    ::view-transition-old(hero) {
+      animation: none;
+      display: none;
+    }
+
+    ::view-transition-new(hero) {
+      animation: none;
+    }
+
+    html:active-view-transition-type(viewer) {
+      &::view-transition-old(hero) {
+        animation: none;
+        display: none;
+      }
+      &::view-transition-new(hero) {
+        animation: var(--vt-duration-default) 0s fadeIn forwards;
+      }
+    }
+
+    html:active-view-transition-type(timeline) {
+      &::view-transition-old(hero) {
+        animation: var(--vt-duration-default) 0s fadeOut forwards;
+      }
+      &::view-transition-new(hero) {
+        animation: var(--vt-duration-default) 0s fadeIn forwards;
+      }
+    }
+
+    ::view-transition-group(letterbox-left),
+    ::view-transition-group(letterbox-right),
+    ::view-transition-group(letterbox-top),
+    ::view-transition-group(letterbox-bottom) {
+      z-index: 100;
+    }
+
+    ::view-transition-old(letterbox-left),
+    ::view-transition-old(letterbox-right),
+    ::view-transition-old(letterbox-top),
+    ::view-transition-old(letterbox-bottom),
+    ::view-transition-new(letterbox-left),
+    ::view-transition-new(letterbox-right),
+    ::view-transition-new(letterbox-top),
+    ::view-transition-new(letterbox-bottom) {
+      background-color: transparent;
+    }
+
+    ::view-transition-group(previous),
+    ::view-transition-group(previous-old),
+    ::view-transition-group(next),
+    ::view-transition-group(next-old) {
+      width: 100% !important;
+      height: 100% !important;
+      transform: none !important;
+    }
+
+    ::view-transition-old(previous),
+    ::view-transition-old(previous-old),
+    ::view-transition-old(next),
+    ::view-transition-old(next-old) {
+      animation: var(--vt-duration-viewer-navigation) fadeOut forwards;
+      transform-origin: center;
+      height: 100%;
+      width: 100%;
+      object-fit: contain;
+      overflow: hidden;
+    }
+
+    ::view-transition-new(previous),
+    ::view-transition-new(previous-new),
+    ::view-transition-new(next),
+    ::view-transition-new(next-new) {
+      animation: var(--vt-duration-viewer-navigation) fadeIn forwards;
+      transform-origin: center;
+      height: 100%;
+      width: 100%;
+      object-fit: contain;
+    }
+  }
+}

web/src/lib/components/AdaptiveImage.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { thumbhash } from '$lib/actions/thumbhash';
   import AlphaBackground from '$lib/components/AlphaBackground.svelte';
+  import Letterboxes from '$lib/components/asset-viewer/letterboxes.svelte';
   import BrokenAsset from '$lib/components/assets/broken-asset.svelte';
   import DelayedLoadingSpinner from '$lib/components/DelayedLoadingSpinner.svelte';
   import ImageLayer from '$lib/components/ImageLayer.svelte';
@@ -18,6 +19,10 @@
     sharedLink?: SharedLinkResponseDto;
     objectFit?: 'contain' | 'cover';
     container: Size;
+    showLetterboxes?: boolean;
+    transitionName?: string | null | undefined;
+    letterboxTransitionName?: string | undefined;
+    imageClass?: string;
     onUrlChange?: (url: string) => void;
     onImageReady?: () => void;
     onError?: () => void;
@@ -41,6 +46,10 @@
     sharedLink,
     objectFit = 'contain',
     container,
+    showLetterboxes = true,
+    transitionName,
+    letterboxTransitionName,
+    imageClass,
     onUrlChange,
     onImageReady,
     onError,
@@ -166,10 +175,20 @@
   });
 </script>
 
-<div class="relative h-full w-full overflow-hidden will-change-transform" bind:this={ref}>
+<div class="relative h-full w-full overflow-hidden" bind:this={ref}>
   {@render backdrop?.()}
 
-  <div class="absolute inset-0 pointer-events-none" style:left style:top style:width style:height>
+  <Letterboxes {letterboxTransitionName} show={showLetterboxes} {scaledDimensions} {container} />
+
+  <div
+    class={['absolute inset-0 pointer-events-none', imageClass]}
+    style:left
+    style:top
+    style:width
+    style:height
+    style:view-transition-name={transitionName}
+    data-transition-name={transitionName}
+  >
     {#if show.alphaBackground}
       <AlphaBackground />
     {/if}

web/src/lib/components/asset-viewer/asset-viewer.svelte

@@ -1,3 +1,9 @@
+<script module lang="ts">
+  const useSplitNavTransitions =
+    typeof document !== 'undefined' &&
+    getComputedStyle(document.documentElement).getPropertyValue('--immich-split-viewer-nav').trim() === 'enabled';
+</script>
+
 <script lang="ts">
   import { browser } from '$app/environment';
   import { focusTrap } from '$lib/actions/focus-trap';
@@ -13,6 +19,7 @@
   import { authManager } from '$lib/managers/auth-manager.svelte';
   import { editManager, EditToolType } from '$lib/managers/edit/edit-manager.svelte';
   import { eventManager } from '$lib/managers/event-manager.svelte';
+  import { viewTransitionManager } from '$lib/managers/ViewTransitionManager.svelte';
   import { getAssetActions } from '$lib/services/asset.service';
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
   import { isFaceEditMode } from '$lib/stores/face-edit.svelte';
@@ -27,6 +34,7 @@
   import { InvocationTracker } from '$lib/utils/invocationTracker';
   import { SlideshowHistory } from '$lib/utils/slideshow-history';
   import { toTimelineAsset } from '$lib/utils/timeline-util';
+  import { crossfadeViewerContent, removeCrossfadeOverlay } from '$lib/utils/transition-utils';
   import {
     AssetTypeEnum,
     getAssetInfo,
@@ -40,7 +48,7 @@
   import { onDestroy, onMount, untrack } from 'svelte';
   import type { SwipeCustomEvent } from 'svelte-gestures';
   import { t } from 'svelte-i18n';
-  import { fly } from 'svelte/transition';
+  import { fly, slide } from 'svelte/transition';
   import Thumbnail from '../assets/thumbnail/thumbnail.svelte';
   import ActivityStatus from './activity-status.svelte';
   import ActivityViewer from './activity-viewer.svelte';
@@ -89,13 +97,14 @@
     onRandom,
   }: Props = $props();
 
-  const { setAssetId } = assetViewingStore;
+  const { setAssetId, invisible } = assetViewingStore;
   const {
     restartProgress: restartSlideshowProgress,
     stopProgress: stopSlideshowProgress,
     slideshowNavigation,
     slideshowState,
     slideshowRepeat,
+    slideshowTransition,
   } = slideshowStore;
   const stackThumbnailSize = 60;
   const stackSelectedThumbnailSize = 65;
@@ -109,6 +118,10 @@
   let sharedLink = getSharedLink();
   let fullscreenElement = $state<Element>();
 
+  let slideShowPlaying = $derived($slideshowState === SlideshowState.PlaySlideshow);
+  let slideShowAscending = $derived($slideshowNavigation === SlideshowNavigation.AscendingOrder);
+  let slideShowShuffle = $derived($slideshowNavigation === SlideshowNavigation.Shuffle);
+
   let playOriginalVideo = $state($alwaysLoadOriginalVideo);
   let slideshowStartAssetId = $state<string>();
 
@@ -142,35 +155,40 @@
     }
   };
 
-  const onAssetUpdate = (updatedAsset: AssetResponseDto) => {
+  let transitionName = $state<string | undefined>('hero');
-    if (asset.id === updatedAsset.id) {
+  let letterboxTransitionName = $state<string | undefined>(undefined);
-      cursor = { ...cursor, current: updatedAsset };
+  let detailPanelTransitionName = $state<string | undefined>(undefined);
-    }
-  };
 
+  let unsubscribes: (() => void)[] = [];
   onMount(() => {
     syncAssetViewerOpenClass(true);
-    const slideshowStateUnsubscribe = slideshowState.subscribe((value) => {
-      if (value === SlideshowState.PlaySlideshow) {
-        slideshowHistory.reset();
-        slideshowHistory.queue(toTimelineAsset(asset));
-        handlePromiseError(handlePlaySlideshow());
-      } else if (value === SlideshowState.StopSlideshow) {
-        handlePromiseError(handleStopSlideshow());
-      }
-    });
 
-    const slideshowNavigationUnsubscribe = slideshowNavigation.subscribe((value) => {
+    const addInfoTransition = () => {
-      if (value === SlideshowNavigation.Shuffle) {
+      detailPanelTransitionName = 'info';
-        slideshowHistory.reset();
+      transitionName = 'hero';
-        slideshowHistory.queue(toTimelineAsset(asset));
-      }
-    });
-
-    return () => {
-      slideshowStateUnsubscribe();
-      slideshowNavigationUnsubscribe();
     };
+
+    unsubscribes.push(
+      eventManager.on({
+        ViewerOpenTransition: addInfoTransition,
+        ViewerCloseTransition: addInfoTransition,
+      }),
+      slideshowState.subscribe((value) => {
+        if (value === SlideshowState.PlaySlideshow) {
+          slideshowHistory.reset();
+          slideshowHistory.queue(toTimelineAsset(asset));
+          handlePromiseError(handlePlaySlideshow());
+        } else if (value === SlideshowState.StopSlideshow) {
+          handlePromiseError(handleStopSlideshow());
+        }
+      }),
+      slideshowNavigation.subscribe((value) => {
+        if (value === SlideshowNavigation.Shuffle) {
+          slideshowHistory.reset();
+          slideshowHistory.queue(toTimelineAsset(asset));
+        }
+      }),
+    );
   });
 
   onDestroy(() => {
@@ -179,10 +197,16 @@
     isFaceEditMode.value = false;
     syncAssetViewerOpenClass(false);
     preloadManager.destroy();
+
+    for (const unsubscribe of unsubscribes) {
+      unsubscribe();
+    }
   });
 
   const closeViewer = () => {
-    onClose?.(asset);
+    transitionName = 'hero';
+    const id = stack?.primaryAssetId ?? asset.id;
+    onClose?.({ ...asset, id });
   };
 
   const closeEditor = async () => {
@@ -194,65 +218,132 @@
     assetViewerManager.closeEditor();
   };
 
+  const getTransitionName = (kind: 'old' | 'new', direction: string | null | undefined) => {
+    if (direction === 'previous' || direction === 'next') {
+      return useSplitNavTransitions ? `${direction}-${kind}` : direction;
+    }
+    return direction ?? undefined;
+  };
+
+  const clearTransitionNames = () => {
+    detailPanelTransitionName = undefined;
+    transitionName = undefined;
+    letterboxTransitionName = undefined;
+  };
+
+  const startTransition = async (
+    types: string[],
+    targetTransition: string | null,
+    navigateFn: () => Promise<boolean>,
+  ) => {
+    const oldName = getTransitionName('old', targetTransition);
+    const newName = getTransitionName('new', targetTransition);
+
+    let result = false;
+
+    await viewTransitionManager.startTransition({
+      types,
+      prepareOldSnapshot: () => {
+        transitionName = oldName;
+        letterboxTransitionName = targetTransition ? `${targetTransition}-old` : undefined;
+        detailPanelTransitionName = 'detail-panel';
+      },
+      performUpdate: async (signal) => {
+        const ready = eventManager.untilNext('ViewerOpenTransitionReady', { signal });
+        result = await navigateFn();
+        await ready;
+      },
+      prepareNewSnapshot: () => {
+        transitionName = newName;
+        letterboxTransitionName = targetTransition ? `${targetTransition}-new` : undefined;
+      },
+      onFinished: clearTransitionNames,
+    });
+
+    return result;
+  };
+
+  const completeNavigation = async (order: 'previous' | 'next', skipTransition: boolean) => {
+    preloadManager.cancelBeforeNavigation(order);
+    const skipped = viewTransitionManager.skipTransitions();
+    const canTransition = viewTransitionManager.isSupported() && !skipped && !skipTransition;
+
+    let navigate: () => Promise<boolean>;
+    let types: string[];
+    let targetTransition: string | null;
+
+    if (slideShowPlaying && slideShowShuffle) {
+      navigate = async () => {
+        let next = order === 'previous' ? slideshowHistory.previous() : slideshowHistory.next();
+        if (!next) {
+          const asset = await onRandom?.();
+          if (asset) {
+            slideshowHistory.queue(asset);
+            next = true;
+          }
+        }
+        return next;
+      };
+      types = ['slideshow'];
+      targetTransition = null;
+    } else {
+      navigate = async () => {
+        const target = order === 'previous' ? previousAsset : nextAsset;
+        return navigateToAsset(target);
+      };
+      types = slideShowPlaying ? ['slideshow'] : ['viewer-nav'];
+      targetTransition = slideShowPlaying ? null : order;
+    }
+
+    const targetAsset = order === 'previous' ? previousAsset : nextAsset;
+    const slideshowAllowsTransition = !slideShowPlaying || $slideshowTransition;
+    const useTransition = canTransition && slideshowAllowsTransition && (slideShowShuffle || !!targetAsset);
+    const hasNext = useTransition ? await startTransition(types, targetTransition, navigate) : await navigate();
+
+    if (!slideShowPlaying) {
+      return;
+    }
+
+    if (hasNext) {
+      $restartSlideshowProgress = true;
+      return;
+    }
+
+    if ($slideshowRepeat && slideshowStartAssetId) {
+      await setAssetId(slideshowStartAssetId);
+      $restartSlideshowProgress = true;
+      return;
+    }
+
+    await handleStopSlideshow();
+  };
+
   const tracker = new InvocationTracker();
-  const navigateAsset = (order?: 'previous' | 'next') => {
+  let navigating = $state(false);
+  const navigateAsset = (order?: 'previous' | 'next', skipTransition: boolean = false) => {
     if (!order) {
-      if ($slideshowState === SlideshowState.PlaySlideshow) {
+      if (slideShowPlaying) {
-        order = $slideshowNavigation === SlideshowNavigation.AscendingOrder ? 'previous' : 'next';
+        order = slideShowAscending ? 'previous' : 'next';
       } else {
         return;
       }
     }
 
-    preloadManager.cancelBeforeNavigation(order);
-
     if (tracker.isActive()) {
       return;
     }
 
-    void tracker.invoke(async () => {
+    navigating = true;
-      const isShuffle =
+    void tracker.invoke(
-        $slideshowState === SlideshowState.PlaySlideshow && $slideshowNavigation === SlideshowNavigation.Shuffle;
+      () => completeNavigation(order, skipTransition),
-
+      (error: unknown) => handleError(error, $t('error_while_navigating')),
-      let hasNext: boolean;
+      () => {
-
+        navigating = false;
-      if (isShuffle) {
+        eventManager.emit('ViewerAfterNavigate');
-        hasNext = order === 'previous' ? slideshowHistory.previous() : slideshowHistory.next();
+      },
-        if (!hasNext) {
+    );
-          const asset = await onRandom?.();
-          if (asset) {
-            slideshowHistory.queue(asset);
-            hasNext = true;
-          }
-        }
-      } else {
-        hasNext =
-          order === 'previous' ? await navigateToAsset(cursor.previousAsset) : await navigateToAsset(cursor.nextAsset);
-      }
-
-      if ($slideshowState !== SlideshowState.PlaySlideshow) {
-        return;
-      }
-
-      if (hasNext) {
-        $restartSlideshowProgress = true;
-        return;
-      }
-
-      if ($slideshowRepeat && slideshowStartAssetId) {
-        await setAssetId(slideshowStartAssetId);
-        $restartSlideshowProgress = true;
-        return;
-      }
-
-      await handleStopSlideshow();
-    }, $t('error_while_navigating'));
   };
 
-  /**
-   * Slide show mode
-   */
-
   let assetViewerHtmlElement = $state<HTMLElement>();
 
   const slideshowHistory = new SlideshowHistory((asset) => {
@@ -277,10 +368,11 @@
 
   const handleStopSlideshow = async () => {
     try {
-      if (document.fullscreenElement) {
+      if (!document.fullscreenElement) {
-        document.body.style.cursor = '';
+        return;
-        await document.exitFullscreen();
       }
+      document.body.style.cursor = '';
+      await document.exitFullscreen();
     } catch (error) {
       handleError(error, $t('errors.unable_to_exit_fullscreen'));
     } finally {
@@ -289,11 +381,24 @@
     }
   };
 
-  const handleStackedAssetMouseEvent = (isMouseOver: boolean, stackedAsset: AssetResponseDto) => {
+  const handleStackedAssetMouseEnter = (stackedAsset: AssetResponseDto) => {
-    previewStackedAsset = isMouseOver ? stackedAsset : undefined;
+    if ((previewStackedAsset ?? cursor.current).id === stackedAsset.id) {
-    if (isMouseOver) {
+      return;
-      isFaceEditMode.value = false;
     }
+
+    isFaceEditMode.value = false;
+    void crossfadeViewerContent(() => {
+      previewStackedAsset = stackedAsset;
+    });
+  };
+
+  const handleStackSlideshowMouseLeave = () => {
+    if (!previewStackedAsset) {
+      return;
+    }
+
+    removeCrossfadeOverlay();
+    previewStackedAsset = undefined;
   };
 
   const handlePreAction = (action: Action) => {
@@ -394,15 +499,24 @@
     if (cursor.current.id === lastCursor?.current.id) {
       return;
     }
+
     if (lastCursor) {
+      previewStackedAsset = undefined;
+      ocrManager.showOverlay = false;
       preloadManager.updateAfterNavigation(lastCursor, cursor, sharedLink);
+      lastCursor = cursor;
+      return;
     }
-    if (!lastCursor) {
+    preloadManager.initializePreloads(cursor, sharedLink);
-      preloadManager.initializePreloads(cursor, sharedLink);
-    }
     lastCursor = cursor;
   });
 
+  const onAssetUpdate = (update: AssetResponseDto) => {
+    if (asset.id === update.id) {
+      cursor = { ...cursor, current: update };
+    }
+  };
+
   const viewerKind = $derived.by(() => {
     if (previewStackedAsset) {
       return previewStackedAsset.type === AssetTypeEnum.Image ? 'PhotoViewer' : 'StackVideoViewer';
@@ -473,13 +587,17 @@
 
 <section
   id="immich-asset-viewer"
-  class="fixed start-0 top-0 grid size-full grid-cols-4 grid-rows-[64px_1fr] overflow-hidden bg-black touch-none"
+  class="fixed inset-s-0 top-0 z-10 grid size-full grid-cols-4 grid-rows-[64px_1fr] overflow-hidden bg-black touch-none"
+  class:invisible={$invisible}
+  data-navigating={navigating || undefined}
   use:focusTrap
   bind:this={assetViewerHtmlElement}
 >
-  <!-- Top navigation bar -->
   {#if $slideshowState === SlideshowState.None && !assetViewerManager.isShowEditor}
-    <div class="col-span-4 col-start-1 row-span-1 row-start-1 transition-transform">
+    <div
+      class="col-span-4 col-start-1 row-span-1 row-start-1 transition-transform"
+      style:view-transition-name="exclude"
+    >
       <AssetViewerNavBar
         {asset}
         {album}
@@ -490,7 +608,7 @@
         onAction={handleAction}
         {onUndoDelete}
         onPlaySlideshow={() => ($slideshowState = SlideshowState.PlaySlideshow)}
-        onClose={onClose ? () => onClose(asset) : undefined}
+        onClose={onClose ? closeViewer : undefined}
         {playOriginalVideo}
         {setPlayOriginalVideo}
       />
@@ -511,16 +629,21 @@
   {/if}
 
   {#if $slideshowState === SlideshowState.None && showNavigation && !assetViewerManager.isShowEditor && !isFaceEditMode.value && previousAsset}
-    <div class="my-auto col-span-1 col-start-1 row-span-full row-start-1 justify-self-start">
+    <div
+      data-test-id="previous-asset"
+      class="my-auto col-span-1 col-start-1 row-span-full row-start-1 justify-self-start"
+      style:view-transition-name="exclude-leftbutton"
+    >
       <PreviousAssetAction onPreviousAsset={() => navigateAsset('previous')} />
     </div>
   {/if}
 
-  <!-- Asset Viewer -->
   <div data-viewer-content class="z-[-1] relative col-start-1 col-span-4 row-start-1 row-span-full">
     {#if viewerKind === 'StackVideoViewer'}
       <VideoViewer
+        {transitionName}
         asset={previewStackedAsset!}
+        assetId={previewStackedAsset!.id}
         cacheKey={previewStackedAsset!.thumbhash}
         projectionType={previewStackedAsset!.exifInfo?.projectionType}
         loopVideo={true}
@@ -533,6 +656,7 @@
       />
     {:else if viewerKind === 'LiveVideoViewer'}
       <VideoViewer
+        {transitionName}
         {asset}
         assetId={asset.livePhotoVideoId!}
         cacheKey={asset.thumbhash}
@@ -544,13 +668,20 @@
         {playOriginalVideo}
       />
     {:else if viewerKind === 'ImagePanaramaViewer'}
-      <ImagePanoramaViewer {asset} />
+      <ImagePanoramaViewer {asset} {transitionName} {letterboxTransitionName} />
     {:else if viewerKind === 'CropArea'}
       <CropArea {asset} />
     {:else if viewerKind === 'PhotoViewer'}
-      <PhotoViewer cursor={{ ...cursor, current: asset }} {sharedLink} {onSwipe} />
+      <PhotoViewer
+        {transitionName}
+        {letterboxTransitionName}
+        cursor={{ ...cursor, current: asset }}
+        {sharedLink}
+        {onSwipe}
+      />
     {:else if viewerKind === 'VideoViewer'}
       <VideoViewer
+        {transitionName}
         {asset}
         cacheKey={asset.thumbhash}
         projectionType={asset.exifInfo?.projectionType}
@@ -584,15 +715,20 @@
   </div>
 
   {#if $slideshowState === SlideshowState.None && showNavigation && !assetViewerManager.isShowEditor && !isFaceEditMode.value && nextAsset}
-    <div class="my-auto col-span-1 col-start-4 row-span-full row-start-1 justify-self-end">
+    <div
+      data-test-id="next-asset"
+      class="my-auto col-span-1 col-start-4 row-span-full row-start-1 justify-self-end"
+      style:view-transition-name="exclude-rightbutton"
+    >
       <NextAssetAction onNextAsset={() => navigateAsset('next')} />
     </div>
   {/if}
 
   {#if showDetailPanel || assetViewerManager.isShowEditor}
     <div
-      transition:fly={{ duration: 150 }}
+      transition:slide={{ axis: 'x', duration: 150 }}
       id="detail-panel"
+      style:view-transition-name={detailPanelTransitionName}
       class="row-start-1 row-span-4 overflow-y-auto transition-all dark:border-l dark:border-s-immich-dark-gray bg-light"
       translate="yes"
     >
@@ -608,9 +744,14 @@
     </div>
   {/if}
 
-  {#if stack && withStacked && !assetViewerManager.isShowEditor}
+  {#if stack && withStacked && !assetViewerManager.isShowEditor && $slideshowState === SlideshowState.None}
     {@const stackedAssets = stack.assets}
-    <div id="stack-slideshow" class="absolute bottom-0 w-full col-span-4 col-start-1 pointer-events-none">
+    <!-- svelte-ignore a11y_no_static_element_interactions -->
+    <div
+      id="stack-slideshow"
+      class="absolute bottom-0 w-full col-span-4 col-start-1 pointer-events-none"
+      onmouseleave={handleStackSlideshowMouseLeave}
+    >
       <div class="relative flex flex-row no-wrap overflow-x-auto overflow-y-hidden horizontal-scrollbar">
         {#each stackedAssets as stackedAsset (stackedAsset.id)}
           <div
@@ -623,11 +764,12 @@
               dimmed={stackedAsset.id !== asset.id}
               asset={toTimelineAsset(stackedAsset)}
               onClick={() => {
+                removeCrossfadeOverlay();
                 cursor.current = stackedAsset;
                 previewStackedAsset = undefined;
                 isFaceEditMode.value = false;
               }}
-              onMouseEvent={({ isMouseOver }) => handleStackedAssetMouseEvent(isMouseOver, stackedAsset)}
+              onMouseEvent={({ isMouseOver }) => isMouseOver && handleStackedAssetMouseEnter(stackedAsset)}
               readonly
               thumbnailSize={stackedAsset.id === asset.id ? stackSelectedThumbnailSize : stackThumbnailSize}
               showStackedIcon={false}

web/src/lib/components/asset-viewer/editor/transform-tool/crop-area.svelte

@@ -7,6 +7,7 @@
   import { Icon } from '@immich/ui';
   import { onMount } from 'svelte';
   import { t } from 'svelte-i18n';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
 
   interface Props {
     asset: AssetResponseDto;
@@ -74,6 +75,8 @@
       alt={$getAltText(toTimelineAsset(asset))}
       class="h-full select-none transition-transform motion-reduce:transition-none"
       style:transform={imageTransform}
+      onload={() => eventManager.emit('ViewerOpenTransitionReady')}
+      onerror={() => eventManager.emit('ViewerOpenTransitionReady')}
     />
     <div
       class={[

web/src/lib/components/asset-viewer/image-panorama-viewer.svelte

@@ -4,13 +4,14 @@
   import { AssetMediaSize, viewAsset, type AssetResponseDto } from '@immich/sdk';
   import { LoadingSpinner } from '@immich/ui';
   import { t } from 'svelte-i18n';
-  import { fade } from 'svelte/transition';
 
   type Props = {
+    transitionName?: string;
+    letterboxTransitionName?: string;
     asset: AssetResponseDto;
   };
 
-  let { asset }: Props = $props();
+  let { transitionName, letterboxTransitionName, asset }: Props = $props();
 
   const assetId = $derived(asset.id);
 
@@ -20,11 +21,16 @@
   };
 </script>
 
-<div transition:fade={{ duration: 150 }} class="flex h-full select-none place-content-center place-items-center">
+<div class="flex h-dvh w-dvw select-none place-content-center place-items-center">
   {#await Promise.all([loadAssetData(assetId), import('./photo-sphere-viewer-adapter.svelte')])}
     <LoadingSpinner />
   {:then [data, { default: PhotoSphereViewer }]}
-    <PhotoSphereViewer panorama={data} originalPanorama={getAssetUrl({ asset, forceOriginal: true })} />
+    <PhotoSphereViewer
+      {transitionName}
+      {letterboxTransitionName}
+      panorama={data}
+      originalPanorama={getAssetUrl({ asset, forceOriginal: true })}
+    />
   {:catch}
     {$t('errors.failed_to_load_asset')}
   {/await}

web/src/lib/components/asset-viewer/letterboxes.svelte

@@ -0,0 +1,68 @@
+<script lang="ts">
+  interface Props {
+    letterboxTransitionName?: string | undefined;
+    show?: boolean;
+    scaledDimensions: {
+      width: number;
+      height: number;
+    };
+    container: {
+      width: number;
+      height: number;
+    };
+  }
+
+  let { letterboxTransitionName, show = true, scaledDimensions, container }: Props = $props();
+
+  const shouldShowLetterboxes = $derived(show && !!letterboxTransitionName);
+
+  const letterboxes = $derived.by(() => {
+    const { width, height } = scaledDimensions;
+    const horizontalOffset = (container.width - width) / 2;
+    const verticalOffset = (container.height - height) / 2;
+
+    return [
+      {
+        name: 'letterbox-left',
+        width: horizontalOffset + 'px',
+        height: container.height + 'px',
+        left: '0px',
+        top: '0px',
+      },
+      {
+        name: 'letterbox-right',
+        width: horizontalOffset + 'px',
+        height: container.height + 'px',
+        left: container.width - horizontalOffset + 'px',
+        top: '0px',
+      },
+      {
+        name: 'letterbox-top',
+        width: width + 'px',
+        height: verticalOffset + 'px',
+        left: horizontalOffset + 'px',
+        top: '0px',
+      },
+      {
+        name: 'letterbox-bottom',
+        width: width + 'px',
+        height: verticalOffset + 'px',
+        left: horizontalOffset + 'px',
+        top: container.height - verticalOffset + 'px',
+      },
+    ];
+  });
+</script>
+
+{#if shouldShowLetterboxes}
+  {#each letterboxes as box (box.name)}
+    <div
+      class="absolute"
+      style:view-transition-name={box.name}
+      style:left={box.left}
+      style:top={box.top}
+      style:width={box.width}
+      style:height={box.height}
+    ></div>
+  {/each}
+{/if}

web/src/lib/components/asset-viewer/photo-sphere-viewer-adapter.svelte

@@ -1,7 +1,9 @@
 <script lang="ts">
   import { shortcuts } from '$lib/actions/shortcut';
   import AssetViewerEvents from '$lib/components/AssetViewerEvents.svelte';
+  import Letterboxes from '$lib/components/asset-viewer/letterboxes.svelte';
   import { assetViewerManager } from '$lib/managers/asset-viewer-manager.svelte';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
   import { ocrManager, type OcrBoundingBox } from '$lib/stores/ocr.svelte';
   import { boundingBoxesArray, type Faces } from '$lib/stores/people.store';
   import { alwaysLoadOriginalFile } from '$lib/stores/preferences.store';
@@ -41,6 +43,8 @@
     'flex items-center justify-center text-white bg-black/50 cursor-text pointer-events-auto whitespace-pre-wrap wrap-break-word select-text';
 
   type Props = {
+    transitionName?: string;
+    letterboxTransitionName?: string;
     panorama: string | { source: string };
     originalPanorama?: string | { source: string };
     adapter?: AdapterConstructor | [AdapterConstructor, unknown];
@@ -48,11 +52,21 @@
     navbar?: boolean;
   };
 
-  let { panorama, originalPanorama, adapter = EquirectangularAdapter, plugins = [], navbar = false }: Props = $props();
+  let {
+    transitionName,
+    letterboxTransitionName,
+    panorama,
+    originalPanorama,
+    adapter = EquirectangularAdapter,
+    plugins = [],
+    navbar = false,
+  }: Props = $props();
 
   let container: HTMLDivElement | undefined = $state();
   let viewer: Viewer;
 
+  const fullscreenDimensions = { width: globalThis.innerWidth || 0, height: globalThis.innerHeight || 0 };
+
   let animationInProgress: { cancel: () => void } | undefined;
   let previousFaces: Faces[] = [];
 
@@ -210,6 +224,7 @@
       zoomSpeed: 0.5,
       fisheye: false,
     });
+    viewer.addEventListener('ready', () => eventManager.emit('ViewerOpenTransitionReady'), { once: true });
     const resolutionPlugin = viewer.getPlugin<ResolutionPlugin>(ResolutionPlugin);
     const zoomHandler = ({ zoomLevel }: events.ZoomUpdatedEvent) => {
       // zoomLevel is 0-100
@@ -254,7 +269,15 @@
 <AssetViewerEvents {onZoom} />
 
 <svelte:document use:shortcuts={[{ shortcut: { key: 'z' }, onShortcut: onZoom, preventDefault: true }]} />
-<div class="h-full w-full mb-0" bind:this={container}></div>
+<div
+  id="sphere"
+  class="h-full w-full h-dvh w-dvw mb-0"
+  bind:this={container}
+  style:view-transition-name={transitionName}
+></div>
+
+<!-- Zero-sized letterboxes for view transitions from/to regular photos -->
+<Letterboxes {letterboxTransitionName} scaledDimensions={fullscreenDimensions} container={fullscreenDimensions} />
 
 <style>
   /* Reset the default tooltip styling */

web/src/lib/components/asset-viewer/photo-viewer.svelte

@@ -8,6 +8,7 @@
   import AssetViewerEvents from '$lib/components/AssetViewerEvents.svelte';
   import { assetViewerManager } from '$lib/managers/asset-viewer-manager.svelte';
   import { castManager } from '$lib/managers/cast-manager.svelte';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
   import { isEditFacesPanelOpen, isFaceEditMode } from '$lib/stores/face-edit.svelte';
   import { ocrManager } from '$lib/stores/ocr.svelte';
   import { boundingBoxesArray, type Faces } from '$lib/stores/people.store';
@@ -29,14 +30,26 @@
     cursor: AssetCursor;
     element?: HTMLDivElement;
     sharedLink?: SharedLinkResponseDto;
-    onReady?: () => void;
+    transitionName?: string;
+    letterboxTransitionName?: string;
     onError?: () => void;
     onSwipe?: (event: SwipeCustomEvent) => void;
   };
 
-  let { cursor, element = $bindable(), sharedLink, onReady, onError, onSwipe }: Props = $props();
+  let {
+    cursor,
+    element = $bindable(),
+    sharedLink,
+    transitionName,
+    letterboxTransitionName,
+    onError,
+    onSwipe,
+  }: Props = $props();
 
   const { slideshowState, slideshowLook } = slideshowStore;
+  const objectFit = $derived(
+    $slideshowState !== SlideshowState.None && $slideshowLook === SlideshowLook.Cover ? 'cover' : 'contain',
+  );
   const asset = $derived(cursor.current);
 
   let visibleImageReady: boolean = $state(false);
@@ -181,20 +194,23 @@
     {asset}
     {sharedLink}
     {container}
-    objectFit={$slideshowState !== SlideshowState.None && $slideshowLook === SlideshowLook.Cover ? 'cover' : 'contain'}
+    {objectFit}
     {onUrlChange}
     onImageReady={() => {
       visibleImageReady = true;
-      onReady?.();
+      eventManager.emit('ViewerOpenTransitionReady');
     }}
     onError={() => {
       onError?.();
-      onReady?.();
+      eventManager.emit('ViewerOpenTransitionReady');
     }}
     bind:imgRef={assetViewerManager.imgRef}
     bind:imgNaturalSize={imageDimensions}
     bind:imgScaledSize={scaledDimensions}
     bind:ref={adaptiveImage}
+    {transitionName}
+    {letterboxTransitionName}
+    showLetterboxes={!blurredSlideshow}
   >
     {#snippet backdrop()}
       {#if blurredSlideshow}

web/src/lib/components/asset-viewer/video-native-viewer.svelte

@@ -3,6 +3,7 @@
   import VideoRemoteViewer from '$lib/components/asset-viewer/video-remote-viewer.svelte';
   import { assetViewerFadeDuration } from '$lib/constants';
   import { castManager } from '$lib/managers/cast-manager.svelte';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
   import { isFaceEditMode } from '$lib/stores/face-edit.svelte';
   import {
     autoPlayVideo,
@@ -19,6 +20,7 @@
   import { fade } from 'svelte/transition';
 
   type Props = {
+    transitionName?: string;
     assetId: string;
     imageSize: Size;
     loopVideo: boolean;
@@ -32,6 +34,7 @@
   };
 
   let {
+    transitionName,
     assetId,
     imageSize,
     loopVideo,
@@ -61,7 +64,6 @@
   });
 
   $effect(() => {
-    // reactive on `assetFileUrl` changes
     if (assetFileUrl) {
       hasFocused = false;
       videoPlayer?.load();
@@ -142,6 +144,7 @@
       </div>
     {:else}
       <video
+        style:view-transition-name={transitionName}
         bind:this={videoPlayer}
         loop={$loopVideoPreference && loopVideo}
         autoplay={$autoPlayVideo}
@@ -150,6 +153,7 @@
         disablePictureInPicture
         class="h-full object-contain"
         {...useSwipe(onSwipe)}
+        onloadedmetadata={() => eventManager.emit('ViewerOpenTransitionReady')}
         oncanplay={(e) => handleCanPlay(e.currentTarget)}
         onended={onVideoEnded}
         onvolumechange={(e) => ($videoViewerMuted = e.currentTarget.muted)}

web/src/lib/components/asset-viewer/video-panorama-viewer.svelte

@@ -3,13 +3,13 @@
   import type { AssetResponseDto } from '@immich/sdk';
   import { LoadingSpinner } from '@immich/ui';
   import { t } from 'svelte-i18n';
-  import { fade } from 'svelte/transition';
 
   interface Props {
+    transitionName?: string;
     asset: AssetResponseDto;
   }
 
-  const { asset }: Props = $props();
+  const { asset, transitionName }: Props = $props();
 
   const modules = Promise.all([
     import('./photo-sphere-viewer-adapter.svelte').then((module) => module.default),
@@ -19,11 +19,12 @@
   ]);
 </script>
 
-<div transition:fade={{ duration: 150 }} class="flex h-full select-none place-content-center place-items-center">
+<div class="flex h-full select-none place-content-center place-items-center">
   {#await modules}
     <LoadingSpinner />
   {:then [PhotoSphereViewer, adapter, videoPlugin]}
     <PhotoSphereViewer
+      {transitionName}
       panorama={{ source: getAssetPlaybackUrl({ id: asset.id }) }}
       originalPanorama={{ source: getAssetUrl({ asset, forceOriginal: true })! }}
       plugins={[videoPlugin]}

web/src/lib/components/asset-viewer/video-wrapper-viewer.svelte

@@ -5,6 +5,7 @@
   import type { AssetResponseDto } from '@immich/sdk';
 
   type Props = {
+    transitionName?: string;
     asset: AssetResponseDto;
     assetId?: string;
     projectionType: string | null | undefined;
@@ -19,6 +20,7 @@
   };
 
   let {
+    transitionName,
     asset,
     assetId,
     projectionType,
@@ -36,9 +38,10 @@
 </script>
 
 {#if projectionType === ProjectionType.EQUIRECTANGULAR}
-  <VideoPanoramaViewer {asset} />
+  <VideoPanoramaViewer {transitionName} {asset} />
 {:else}
   <VideoNativeViewer
+    {transitionName}
     {loopVideo}
     {cacheKey}
     assetId={effectiveAssetId}

web/src/lib/components/layouts/user-page-layout.svelte

@@ -6,10 +6,11 @@
   import { useActions, type ActionArray } from '$lib/actions/use-actions';
   import NavigationBar from '$lib/components/shared-components/navigation-bar/navigation-bar.svelte';
   import UserSidebar from '$lib/components/shared-components/side-bar/user-sidebar.svelte';
+  import { appManager } from '$lib/managers/app-manager.svelte';
   import type { HeaderButtonActionItem } from '$lib/types';
   import { openFileUploadDialog } from '$lib/utils/file-uploader';
   import { Button, ContextMenuButton, HStack, isMenuItemType, type MenuItemType } from '@immich/ui';
-  import type { Snippet } from 'svelte';
+  import { type Snippet } from 'svelte';
   import { t } from 'svelte-i18n';
 
   interface Props {
@@ -44,12 +45,17 @@
 
   let scrollbarClass = $derived(scrollbar ? 'immich-scrollbar' : 'scrollbar-hidden');
   let hasTitleClass = $derived(title ? 'top-16 h-[calc(100%-(--spacing(16)))]' : 'top-0 h-full');
+  let isAssetViewer = $derived(appManager.isAssetViewer);
 </script>
 
 <header>
-  {#if !hideNavbar}
+  {#if !hideNavbar && !isAssetViewer}
     <NavigationBar onUploadClick={() => openFileUploadDialog()} />
   {/if}
+
+  {#if isAssetViewer}
+    <div class="max-md:h-(--navbar-height-md) h-(--navbar-height)"></div>
+  {/if}
 </header>
 <div
   tabindex="-1"
@@ -58,13 +64,15 @@
     {hideNavbar ? 'pt-(--navbar-height)' : ''}
     {hideNavbar ? 'max-md:pt-(--navbar-height-md)' : ''}"
 >
-  {#if sidebar}
+  {#if isAssetViewer}
+    <div></div>
+  {:else if sidebar}
     {@render sidebar()}
   {:else}
     <UserSidebar />
   {/if}
 
-  <main class="relative">
+  <main class="relative w-full">
     <div class="{scrollbarClass} absolute {hasTitleClass} w-full overflow-y-auto p-2" use:useActions={use}>
       {@render children?.()}
     </div>

web/src/lib/components/shared-components/gallery-viewer/gallery-viewer.svelte

@@ -3,10 +3,13 @@
   import { shortcuts, type ShortcutOptions } from '$lib/actions/shortcut';
   import type { Action } from '$lib/components/asset-viewer/actions/action';
   import Thumbnail from '$lib/components/assets/thumbnail/thumbnail.svelte';
+  import { focusAsset } from '$lib/components/timeline/actions/focus-actions';
   import { AssetAction } from '$lib/constants';
   import Portal from '$lib/elements/Portal.svelte';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
   import { featureFlagsManager } from '$lib/managers/feature-flags-manager.svelte';
   import type { TimelineAsset, Viewport } from '$lib/managers/timeline-manager/types';
+  import { viewTransitionManager } from '$lib/managers/ViewTransitionManager.svelte';
   import AssetDeleteConfirmModal from '$lib/modals/AssetDeleteConfirmModal.svelte';
   import ShortcutsModal from '$lib/modals/ShortcutsModal.svelte';
   import { Route } from '$lib/route';
@@ -27,9 +30,11 @@
   import { getJustifiedLayoutFromAssets } from '$lib/utils/layout-utils';
   import { navigate } from '$lib/utils/navigation';
   import { isTimelineAsset, toTimelineAsset } from '$lib/utils/timeline-util';
+  import { startViewerTransition } from '$lib/utils/transition-utils';
   import { AssetVisibility, type AssetResponseDto } from '@immich/sdk';
   import { modalManager } from '@immich/ui';
   import { debounce } from 'lodash-es';
+  import { onMount, tick } from 'svelte';
   import { t } from 'svelte-i18n';
 
   type Props = {
@@ -65,6 +70,16 @@
   }: Props = $props();
 
   let { isViewing: isViewerOpen, asset: viewingAsset } = assetViewingStore;
+
+  $effect(() => {
+    if ($isViewerOpen) {
+      document.documentElement.style.overflow = 'hidden';
+    }
+    return () => {
+      document.documentElement.style.overflow = '';
+    };
+  });
+
   const navigationAssets = $derived(viewerAssets ?? assets);
 
   const geometry = $derived(
@@ -107,6 +122,36 @@
 
   const updateSlidingWindow = () => (scrollTop = document.scrollingElement?.scrollTop ?? 0);
 
+  const scrollGalleryToAsset = async (assetId: string) => {
+    const index = assets.findIndex((asset) => asset.id === assetId);
+    if (index === -1) {
+      return;
+    }
+    const assetTopPage = geometry.getTop(index) + slidingWindowOffset;
+    const assetBottomPage = assetTopPage + geometry.getHeight(index);
+    const currentScrollTop = document.scrollingElement?.scrollTop ?? 0;
+    const visibleTop = currentScrollTop + pageHeaderOffset;
+    const visibleBottom = currentScrollTop + viewport.height;
+
+    if (assetTopPage >= visibleTop && assetBottomPage <= visibleBottom) {
+      return;
+    }
+    const distanceToAlignTop = Math.abs(assetTopPage - pageHeaderOffset - currentScrollTop);
+    const distanceToAlignBottom = Math.abs(assetBottomPage - viewport.height - currentScrollTop);
+    const newScrollTop =
+      distanceToAlignTop < distanceToAlignBottom ? assetTopPage - pageHeaderOffset : assetBottomPage - viewport.height;
+    if (document.scrollingElement) {
+      document.scrollingElement.scrollTop = newScrollTop;
+    }
+    updateSlidingWindow();
+    await tick();
+  };
+
+  const scrollToAndFocusAsset = async (assetId: string) => {
+    await scrollGalleryToAsset(assetId);
+    focusAsset(assetId);
+  };
+
   const debouncedOnIntersected = debounce(() => onIntersected?.(), 750, { maxWait: 100, leading: true });
 
   let lastIntersectedHeight = 0;
@@ -356,6 +401,63 @@
     nextAsset: getNextAsset(navigationAssets, $viewingAsset),
     previousAsset: getPreviousAsset(navigationAssets, $viewingAsset),
   });
+
+  let toViewerTransitionId = $state<string | null>(null);
+  let toGalleryTransitionId = $state<string | null>(null);
+  const transitionTargetId = $derived(toViewerTransitionId ?? toGalleryTransitionId);
+
+  const handleThumbnailClick = (asset: AssetResponseDto, currentAsset: TimelineAsset) => {
+    if (assetInteraction.selectionActive) {
+      handleSelectAssets(currentAsset);
+      return;
+    }
+
+    const doNavigate = () => void navigateToAsset(asset);
+
+    if (!viewTransitionManager.isSupported()) {
+      doNavigate();
+      return;
+    }
+
+    startViewerTransition(asset.id, doNavigate, (id) => (toViewerTransitionId = id));
+  };
+
+  const transitionToGalleryCallback = ({ id }: { id: string }) => {
+    void viewTransitionManager.startTransition({
+      types: ['timeline'],
+      prepareOldSnapshot: () => {
+        void scrollGalleryToAsset(id);
+      },
+      performUpdate: async () => {
+        eventManager.emit('ViewerCloseTransitionReady');
+        toGalleryTransitionId = id;
+        await tick();
+      },
+      onFinished: () => {
+        toGalleryTransitionId = null;
+        focusAsset(id);
+      },
+    });
+  };
+
+  if (viewTransitionManager.isSupported()) {
+    onMount(() => eventManager.on({ ViewerCloseTransition: transitionToGalleryCallback }));
+  }
+
+  const handleClose = async (asset: { id: string }) => {
+    const useTransition = viewTransitionManager.isSupported();
+    if (useTransition) {
+      const transitionReady = eventManager.untilNext('ViewerCloseTransitionReady');
+      eventManager.emit('ViewerCloseTransition', { id: asset.id });
+      await transitionReady;
+    }
+    assetViewingStore.showAssetViewer(false);
+    if (!useTransition) {
+      await tick();
+      await scrollToAndFocusAsset(asset.id);
+    }
+    handlePromiseError(navigate({ targetRoute: 'current', assetId: null }, { noScroll: true }));
+  };
 </script>
 
 <svelte:document
@@ -375,16 +477,17 @@
     {#each assets as asset, i (asset.id + '-' + i)}
       {#if isIntersecting(i)}
         {@const currentAsset = toTimelineAsset(asset)}
-        <div class="absolute" style:overflow="clip" style={getStyle(i)}>
+        {@const transitionName = transitionTargetId === asset.id ? 'hero' : undefined}
+        <div
+          class="absolute"
+          style:overflow="clip"
+          style={getStyle(i)}
+          style:view-transition-name={transitionName}
+          data-transition-name={transitionName}
+        >
           <Thumbnail
             readonly={disableAssetSelect}
-            onClick={() => {
+            onClick={() => handleThumbnailClick(asset, currentAsset)}
-              if (assetInteraction.selectionActive) {
-                handleSelectAssets(currentAsset);
-                return;
-              }
-              void navigateToAsset(asset);
-            }}
             onSelect={() => handleSelectAssets(currentAsset)}
             onMouseEvent={() => assetMouseEventHandler(currentAsset)}
             {showArchiveIcon}
@@ -416,10 +519,7 @@
         onAction={handleAction}
         onRandom={handleRandom}
         onAssetChange={updateCurrentAsset}
-        onClose={() => {
+        onClose={(asset) => handleClose(asset)}
-          assetViewingStore.showAssetViewer(false);
-          handlePromiseError(navigate({ targetRoute: 'current', assetId: null }));
-        }}
       />
     {/await}
   </Portal>

web/src/lib/components/shared-components/navigation-bar/navigation-bar.svelte

@@ -50,7 +50,11 @@
 
 <svelte:window bind:innerWidth />
 
-<nav id="dashboard-navbar" class="max-md:h-(--navbar-height-md) h-(--navbar-height) w-dvw text-sm">
+<nav
+  id="dashboard-navbar"
+  class="max-md:h-(--navbar-height-md) h-(--navbar-height) w-dvw text-sm relative z-10"
+  style:view-transition-name="exclude"
+>
   <SkipLink text={$t('skip_to_content')} />
   <div
     class="grid h-full grid-cols-[--spacing(32)_auto] items-center py-2 sidebar:grid-cols-[--spacing(64)_auto] {noBorder

web/src/lib/components/timeline/AssetLayout.svelte

@@ -1,20 +1,19 @@
 <script lang="ts">
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+  import { filterIntersecting } from '$lib/managers/timeline-manager/utils.svelte';
   import type { ViewerAsset } from '$lib/managers/timeline-manager/viewer-asset.svelte';
-  import type { VirtualScrollManager } from '$lib/managers/VirtualScrollManager/VirtualScrollManager.svelte';
   import { uploadAssetsStore } from '$lib/stores/upload';
   import type { CommonPosition } from '$lib/utils/layout-utils';
   import type { Snippet } from 'svelte';
   import { flip } from 'svelte/animate';
   import { scale } from 'svelte/transition';
 
-  let { isUploading } = uploadAssetsStore;
-
   type Props = {
+    animationTargetAssetId?: string | null;
+    suspendTransitions?: boolean;
     viewerAssets: ViewerAsset[];
     width: number;
     height: number;
-    manager: VirtualScrollManager;
     thumbnail: Snippet<
       [
         {
@@ -26,14 +25,20 @@
     customThumbnailLayout?: Snippet<[asset: TimelineAsset]>;
   };
 
-  const { viewerAssets, width, height, manager, thumbnail, customThumbnailLayout }: Props = $props();
+  let { isUploading } = uploadAssetsStore;
 
-  const transitionDuration = $derived(manager.suspendTransitions && !$isUploading ? 0 : 150);
+  const {
+    animationTargetAssetId,
+    suspendTransitions = false,
+    viewerAssets,
+    width,
+    height,
+    thumbnail,
+    customThumbnailLayout,
+  }: Props = $props();
+
+  const transitionDuration = $derived(suspendTransitions && !$isUploading ? 0 : 150);
   const scaleDuration = $derived(transitionDuration === 0 ? 0 : transitionDuration + 100);
-
-  const filterIntersecting = <T extends { intersecting: boolean }>(intersectables: T[]) => {
-    return intersectables.filter(({ intersecting }) => intersecting);
-  };
 </script>
 
 <!-- Image grid -->
@@ -41,11 +46,14 @@
   {#each filterIntersecting(viewerAssets) as viewerAsset (viewerAsset.id)}
     {@const position = viewerAsset.position!}
     {@const asset = viewerAsset.asset!}
+    {@const transitionName = animationTargetAssetId === asset.id ? 'hero' : undefined}
 
     <!-- note: don't remove data-asset-id - its used by web e2e tests -->
     <div
       data-asset-id={asset.id}
       class="absolute"
+      data-transition-name={transitionName}
+      style:view-transition-name={transitionName}
       style:top={position.top + 'px'}
       style:inset-inline-start={position.left + 'px'}
       style:width={position.width + 'px'}

web/src/lib/components/timeline/Month.svelte

@@ -1,34 +1,37 @@
 <script lang="ts">
+  import { focusAsset } from '$lib/components/timeline/actions/focus-actions';
   import AssetLayout from '$lib/components/timeline/AssetLayout.svelte';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
   import { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
   import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
-  import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
+  import { assetsSnapshot, filterIntersecting } from '$lib/managers/timeline-manager/utils.svelte';
-  import type { VirtualScrollManager } from '$lib/managers/VirtualScrollManager/VirtualScrollManager.svelte';
+  import { viewTransitionManager } from '$lib/managers/ViewTransitionManager.svelte';
   import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { uploadAssetsStore } from '$lib/stores/upload';
   import type { CommonPosition } from '$lib/utils/layout-utils';
   import { fromTimelinePlainDate, getDateLocaleString } from '$lib/utils/timeline-util';
   import { Icon } from '@immich/ui';
   import { mdiCheckCircle, mdiCircleOutline } from '@mdi/js';
-  import type { Snippet } from 'svelte';
+  import { onMount, tick, type Snippet } from 'svelte';
 
   type Props = {
+    toAssetViewerTransitionId?: string | null;
     thumbnail: Snippet<[{ asset: TimelineAsset; position: CommonPosition; dayGroup: DayGroup; groupIndex: number }]>;
     customThumbnailLayout?: Snippet<[TimelineAsset]>;
     singleSelect: boolean;
     assetInteraction: AssetInteraction;
     monthGroup: MonthGroup;
-    manager: VirtualScrollManager;
     onDayGroupSelect: (dayGroup: DayGroup, assets: TimelineAsset[]) => void;
   };
+
   let {
+    toAssetViewerTransitionId,
     thumbnail: thumbnailWithGroup,
     customThumbnailLayout,
     singleSelect,
     assetInteraction,
     monthGroup,
-    manager,
     onDayGroupSelect,
   }: Props = $props();
 
@@ -37,10 +40,6 @@
 
   const transitionDuration = $derived(monthGroup.timelineManager.suspendTransitions && !$isUploading ? 0 : 150);
 
-  const filterIntersecting = <T extends { intersecting: boolean }>(intersectables: T[]) => {
-    return intersectables.filter(({ intersecting }) => intersecting);
-  };
-
   const getDayGroupFullDate = (dayGroup: DayGroup): string => {
     const { month, year } = dayGroup.monthGroup.yearMonth;
     const date = fromTimelinePlainDate({
@@ -50,6 +49,32 @@
     });
     return getDateLocaleString(date);
   };
+
+  let toTimelineTransitionAssetId = $state<string | null>(null);
+  let animationTargetAssetId = $derived(toTimelineTransitionAssetId ?? toAssetViewerTransitionId ?? null);
+
+  const transitionToTimelineCallback = ({ id }: { id: string }) => {
+    const asset = monthGroup.findAssetById({ id });
+    if (!asset) {
+      return;
+    }
+    void viewTransitionManager.startTransition({
+      types: ['timeline'],
+      performUpdate: async () => {
+        eventManager.emit('ViewerCloseTransitionReady');
+        const event = await eventManager.untilNext('TimelineLoaded');
+        toTimelineTransitionAssetId = event.id;
+        await tick();
+      },
+      onFinished: () => {
+        toTimelineTransitionAssetId = null;
+        focusAsset(asset.id);
+      },
+    });
+  };
+  if (viewTransitionManager.isSupported()) {
+    onMount(() => eventManager.on({ ViewerCloseTransition: transitionToTimelineCallback }));
+  }
 </script>
 
 {#each filterIntersecting(monthGroup.dayGroups) as dayGroup, groupIndex (dayGroup.day)}
@@ -93,7 +118,8 @@
     </div>
 
     <AssetLayout
-      {manager}
+      {animationTargetAssetId}
+      suspendTransitions={monthGroup.timelineManager.suspendTransitions}
       viewerAssets={dayGroup.viewerAssets}
       height={dayGroup.height}
       width={dayGroup.width}

web/src/lib/components/timeline/Scrubber.svelte

@@ -11,6 +11,7 @@
   import { fade, fly } from 'svelte/transition';
 
   interface Props {
+    invisible: boolean;
     /** Offset from the top of the timeline (e.g., for headers) */
     timelineTopOffset?: number;
     /** Offset from the bottom of the timeline (e.g., for footers) */
@@ -39,6 +40,7 @@
   }
 
   let {
+    invisible = false,
     timelineTopOffset = 0,
     timelineBottomOffset = 0,
     height = 0,
@@ -438,7 +440,7 @@
           next = forward
             ? (focusable[(index + 1) % focusable.length] as HTMLElement)
             : (focusable[(index - 1) % focusable.length] as HTMLElement);
-          next.focus();
+          next?.focus();
         }
       }
     }
@@ -509,6 +511,7 @@
   aria-valuemin={toScrollY(0)}
   data-id="scrubber"
   class="absolute end-0 z-1 select-none hover:cursor-row-resize"
+  class:invisible
   style:padding-top={PADDING_TOP + 'px'}
   style:padding-bottom={PADDING_BOTTOM + 'px'}
   style:width

web/src/lib/components/timeline/Timeline.svelte

@@ -11,6 +11,8 @@
   import HotModuleReload from '$lib/elements/HotModuleReload.svelte';
   import Portal from '$lib/elements/Portal.svelte';
   import Skeleton from '$lib/elements/Skeleton.svelte';
+  import { startViewerTransition } from '$lib/utils/transition-utils';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
   import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
   import { isIntersecting } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
   import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
@@ -102,6 +104,7 @@
   // Overall scroll percentage through the entire timeline (0-1)
   let timelineScrollPercent: number = $state(0);
   let scrubberWidth = $state(0);
+  let toAssetViewerTransitionId = $state<string | null>(null);
 
   const isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
   const maxMd = $derived(mediaQueryManager.maxMd);
@@ -209,7 +212,7 @@
         timelineManager.viewportWidth = rect.width;
       }
     }
-    const scrollTarget = $gridScrollTarget?.at;
+    const scrollTarget = getScrollTarget();
     let scrolled = false;
     if (scrollTarget) {
       scrolled = await scrollAndLoadAsset(scrollTarget);
@@ -221,7 +224,7 @@
       await tick();
       focusAsset(scrollTarget);
     }
-    invisible = false;
+    invisible = isAssetViewerRoute(page) ? true : false;
   };
 
   // note: only modified once in afterNavigate()
@@ -239,10 +242,13 @@
     hasNavigatedToOrFromAssetViewer = isNavigatingToAssetViewer !== isNavigatingFromAssetViewer;
   });
 
+  const getScrollTarget = () => {
+    return $gridScrollTarget?.at ?? page.params.assetId ?? null;
+  };
   // afterNavigate is only called after navigation to a new URL, {complete} will resolve
   // after successful navigation.
   afterNavigate(({ complete }) => {
-    void complete.finally(() => {
+    void complete.finally(async () => {
       const isAssetViewerPage = isAssetViewerRoute(page);
 
       // Set initial load state only once - if initialLoadWasAssetViewer is null, then
@@ -251,8 +257,13 @@
       if (isDirectNavigation) {
         initialLoadWasAssetViewer = isAssetViewerPage && !hasNavigatedToOrFromAssetViewer;
       }
-
       void scrollAfterNavigate();
+      if (!isAssetViewerPage) {
+        const scrollTarget = getScrollTarget();
+        await tick();
+
+        eventManager.emit('TimelineLoaded', { id: scrollTarget });
+      }
     });
   });
 
@@ -260,7 +271,7 @@
   // note: don't throttle, debounch, or otherwise do this function async - it causes flicker
 
   onMount(() => {
-    if (!enableRouting) {
+    if (!enableRouting && !isAssetViewerRoute(page)) {
       invisible = false;
     }
   });
@@ -524,6 +535,33 @@
     }
   });
 
+  const defaultThumbnailClick = (
+    timelineManager: TimelineManager,
+    assets: TimelineAsset[],
+    groupTitle: string,
+    asset: TimelineAsset,
+  ) => {
+    if (isSelectionMode || assetInteraction.selectionActive) {
+      assetSelectHandler(timelineManager, asset, assets, groupTitle);
+      return;
+    }
+    void navigate({ targetRoute: 'current', assetId: asset.id });
+  };
+
+  const handleThumbnailClick = (asset: TimelineAsset, dayGroup: DayGroup) => {
+    if (typeof onThumbnailClick === 'function' || isSelectionMode || assetInteraction.selectionActive) {
+      if (typeof onThumbnailClick === 'function') {
+        onThumbnailClick(asset, timelineManager, dayGroup, defaultThumbnailClick);
+      } else {
+        defaultThumbnailClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
+      }
+      return;
+    }
+
+    const openViewer = () => void navigate({ targetRoute: 'current', assetId: asset.id });
+    startViewerTransition(asset.id, openViewer, (id) => (toAssetViewerTransitionId = id));
+  };
+
   const assetSelectHandler = (
     timelineManager: TimelineManager,
     asset: TimelineAsset,
@@ -544,19 +582,6 @@
 
     assetInteraction.selectAll = timelineManager.assetCount === assetInteraction.selectedAssets.length;
   };
-
-  const _onClick = (
-    timelineManager: TimelineManager,
-    assets: TimelineAsset[],
-    groupTitle: string,
-    asset: TimelineAsset,
-  ) => {
-    if (isSelectionMode || assetInteraction.selectionActive) {
-      assetSelectHandler(timelineManager, asset, assets, groupTitle);
-      return;
-    }
-    void navigate({ targetRoute: 'current', assetId: asset.id });
-  };
 </script>
 
 <svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} />
@@ -587,6 +612,7 @@
 {#if timelineManager.months.length > 0}
   <Scrubber
     {timelineManager}
+    {invisible}
     height={timelineManager.viewportHeight}
     timelineTopOffset={timelineManager.topSectionHeight}
     timelineBottomOffset={timelineManager.bottomSectionHeight}
@@ -618,6 +644,7 @@
   id="asset-grid"
   class={['scrollbar-hidden h-full overflow-y-auto outline-none', { 'm-0': isEmpty }, { 'ms-0': !isEmpty }]}
   style:margin-inline-end={(usingMobileDevice ? 0 : scrubberWidth) + 'px'}
+  data-initialized={timelineManager.isInitialized || undefined}
   tabindex="-1"
   bind:clientHeight={timelineManager.viewportHeight}
   bind:clientWidth={timelineManager.viewportWidth}
@@ -666,11 +693,11 @@
           style:width="100%"
         >
           <Month
+            {toAssetViewerTransitionId}
             {assetInteraction}
             {customThumbnailLayout}
             {singleSelect}
             {monthGroup}
-            manager={timelineManager}
             onDayGroupSelect={handleGroupSelect}
           >
             {#snippet thumbnail({ asset, position, dayGroup, groupIndex })}
@@ -684,13 +711,7 @@
                 {asset}
                 {albumUsers}
                 {groupIndex}
-                onClick={(asset) => {
+                onClick={(asset) => handleThumbnailClick(asset, dayGroup)}
-                  if (typeof onThumbnailClick === 'function') {
-                    onThumbnailClick(asset, timelineManager, dayGroup, _onClick);
-                  } else {
-                    _onClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
-                  }
-                }}
                 onSelect={() => {
                   if (isSelectionMode || assetInteraction.selectionActive) {
                     assetSelectHandler(timelineManager, asset, dayGroup.getAssets(), dayGroup.groupTitle);

web/src/lib/components/timeline/TimelineAssetViewer.svelte

@@ -4,6 +4,8 @@
   import { AssetAction } from '$lib/constants';
   import { assetCacheManager } from '$lib/managers/AssetCacheManager.svelte';
   import { authManager } from '$lib/managers/auth-manager.svelte';
+  import { eventManager } from '$lib/managers/event-manager.svelte';
+  import { viewTransitionManager } from '$lib/managers/ViewTransitionManager.svelte';
   import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
@@ -98,6 +100,12 @@
   };
 
   const handleClose = async (asset: { id: string }) => {
+    if (viewTransitionManager.isSupported()) {
+      const transitionReady = eventManager.untilNext('ViewerCloseTransitionReady');
+      eventManager.emit('ViewerCloseTransition', { id: asset.id });
+      await transitionReady;
+    }
+
     invisible = true;
     $gridScrollTarget = { at: asset.id };
     await navigate({ targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget });

web/src/lib/managers/ViewTransitionManager.svelte.spec.ts

@@ -0,0 +1,363 @@
+import { ViewTransitionManager } from '$lib/managers/ViewTransitionManager.svelte';
+
+describe('ViewTransitionManager', () => {
+  let manager: ViewTransitionManager;
+
+  beforeEach(() => {
+    manager = new ViewTransitionManager();
+  });
+
+  afterEach(() => {
+    delete (document as Partial<typeof document> & { startViewTransition?: unknown }).startViewTransition;
+  });
+
+  describe('when View Transition API is not supported', () => {
+    it('should still call performUpdate', async () => {
+      const performUpdate = vi.fn().mockResolvedValue(undefined);
+
+      await manager.startTransition({ performUpdate });
+
+      expect(performUpdate).toHaveBeenCalledOnce();
+    });
+
+    it('should call onFinished after performUpdate', async () => {
+      const callOrder: string[] = [];
+      const performUpdate = vi.fn().mockImplementation(() => {
+        callOrder.push('performUpdate');
+      });
+      const onFinished = vi.fn().mockImplementation(() => {
+        callOrder.push('onFinished');
+      });
+
+      await manager.startTransition({ performUpdate, onFinished });
+
+      expect(onFinished).toHaveBeenCalledOnce();
+      expect(callOrder).toEqual(['performUpdate', 'onFinished']);
+    });
+
+    it('should not call prepareOldSnapshot or prepareNewSnapshot', async () => {
+      const prepareOldSnapshot = vi.fn();
+      const prepareNewSnapshot = vi.fn();
+      const performUpdate = vi.fn().mockResolvedValue(undefined);
+
+      await manager.startTransition({ performUpdate, prepareOldSnapshot, prepareNewSnapshot });
+
+      expect(prepareOldSnapshot).not.toHaveBeenCalled();
+      expect(prepareNewSnapshot).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('when a transition is already active', () => {
+    it('should skip the second transition', async () => {
+      let resolveFinished!: () => void;
+      const finished = new Promise<void>((resolve) => {
+        resolveFinished = resolve;
+      });
+      let resolveUpdate!: () => void;
+      const updateCallbackDone = new Promise<void>((resolve) => {
+        resolveUpdate = resolve;
+      });
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return { updateCallbackDone, finished, ready: Promise.resolve(), skipTransition: vi.fn() };
+      });
+
+      const secondPerformUpdate = vi.fn().mockResolvedValue(undefined);
+
+      // Start first — it will be blocked on updateCallbackDone
+      const firstPromise = manager.startTransition({
+        performUpdate: async () => {},
+      });
+
+      // Flush microtasks so the first transition reaches the startViewTransition call
+      await new Promise<void>((r) => queueMicrotask(r));
+
+      // While first is active, try a second — should be skipped
+      await manager.startTransition({ performUpdate: secondPerformUpdate });
+      expect(secondPerformUpdate).not.toHaveBeenCalled();
+
+      // Clean up
+      resolveUpdate();
+      resolveFinished();
+      await firstPromise;
+    });
+  });
+
+  describe('skipTransitions', () => {
+    it('should return false when no transition is active', () => {
+      expect(manager.skipTransitions()).toBe(false);
+    });
+
+    it('should call skipTransition on the active transition and return true', async () => {
+      let resolveFinished!: () => void;
+      const finished = new Promise<void>((resolve) => {
+        resolveFinished = resolve;
+      });
+      let resolveUpdate!: () => void;
+      const updateCallbackDone = new Promise<void>((resolve) => {
+        resolveUpdate = resolve;
+      });
+      const skipTransition = vi.fn();
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return { updateCallbackDone, finished, ready: Promise.resolve(), skipTransition };
+      });
+
+      const promise = manager.startTransition({ performUpdate: async () => {} });
+      await new Promise<void>((r) => queueMicrotask(r));
+
+      const skipped = manager.skipTransitions();
+      expect(skipped).toBe(true);
+      expect(skipTransition).toHaveBeenCalledOnce();
+
+      resolveUpdate();
+      resolveFinished();
+      await promise;
+    });
+
+    it('should allow a new transition after skipping', async () => {
+      let resolveFinished!: () => void;
+      const finished = new Promise<void>((resolve) => {
+        resolveFinished = resolve;
+      });
+      let resolveUpdate!: () => void;
+      const updateCallbackDone = new Promise<void>((resolve) => {
+        resolveUpdate = resolve;
+      });
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return { updateCallbackDone, finished, ready: Promise.resolve(), skipTransition: vi.fn() };
+      });
+
+      const promise = manager.startTransition({ performUpdate: async () => {} });
+      await new Promise<void>((r) => queueMicrotask(r));
+
+      manager.skipTransitions();
+      resolveUpdate();
+      resolveFinished();
+      await promise;
+
+      // Now start a second transition — it should NOT be skipped
+      const secondUpdate = vi.fn().mockResolvedValue(undefined);
+      const secondFinished = Promise.resolve();
+      const secondUpdateDone = Promise.resolve();
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return {
+          updateCallbackDone: secondUpdateDone,
+          finished: secondFinished,
+          ready: Promise.resolve(),
+          skipTransition: vi.fn(),
+        };
+      });
+
+      await manager.startTransition({ performUpdate: secondUpdate });
+      expect(secondUpdate).toHaveBeenCalledOnce();
+    });
+  });
+
+  describe('error handling', () => {
+    it('should propagate error from performUpdate when API is not supported', async () => {
+      const error = new Error('update failed');
+      const performUpdate = vi.fn().mockRejectedValue(error);
+
+      await expect(manager.startTransition({ performUpdate })).rejects.toThrow('update failed');
+    });
+
+    it('should clean up activeViewTransition when performUpdate throws (API supported)', async () => {
+      const error = new Error('update failed');
+      let resolveFinished!: () => void;
+      const finished = new Promise<void>((resolve) => {
+        resolveFinished = resolve;
+      });
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        const updateCallbackDone = updateFn();
+        return { updateCallbackDone, finished, ready: Promise.resolve(), skipTransition: vi.fn() };
+      });
+
+      await expect(manager.startTransition({ performUpdate: () => Promise.reject(error) })).rejects.toThrow(
+        'update failed',
+      );
+
+      // Simulate transition finishing after error
+      resolveFinished();
+      await new Promise<void>((r) => queueMicrotask(r));
+
+      // Manager should accept new transitions after cleanup
+      const secondUpdate = vi.fn().mockResolvedValue(undefined);
+      const secondFinished = Promise.resolve();
+      const secondUpdateDone = Promise.resolve();
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return {
+          updateCallbackDone: secondUpdateDone,
+          finished: secondFinished,
+          ready: Promise.resolve(),
+          skipTransition: vi.fn(),
+        };
+      });
+
+      await manager.startTransition({ performUpdate: secondUpdate });
+      expect(secondUpdate).toHaveBeenCalledOnce();
+    });
+  });
+
+  describe('fallback path', () => {
+    it('should fall back to function argument when object argument throws', async () => {
+      const performUpdate = vi.fn().mockResolvedValue(undefined);
+      const prepareNewSnapshot = vi.fn();
+      const finished = Promise.resolve();
+      const updateCallbackDone = Promise.resolve();
+
+      let callCount = 0;
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        callCount++;
+        if (callCount === 1 && typeof arg !== 'function') {
+          throw new TypeError('object form not supported');
+        }
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return { updateCallbackDone, finished, ready: Promise.resolve(), skipTransition: vi.fn() };
+      });
+
+      await manager.startTransition({ performUpdate, prepareNewSnapshot, types: ['test'] });
+
+      expect(performUpdate).toHaveBeenCalledOnce();
+      expect(prepareNewSnapshot).toHaveBeenCalledOnce();
+      // eslint-disable-next-line tscompat/tscompat
+      expect(document.startViewTransition).toHaveBeenCalledTimes(2);
+    });
+  });
+
+  describe('abort signal', () => {
+    it('should pass an AbortSignal to performUpdate', async () => {
+      const performUpdate = vi.fn().mockResolvedValue(undefined);
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return {
+          updateCallbackDone: Promise.resolve(),
+          finished: Promise.resolve(),
+          ready: Promise.resolve(),
+          skipTransition: vi.fn(),
+        };
+      });
+
+      await manager.startTransition({ performUpdate });
+
+      expect(performUpdate).toHaveBeenCalledWith(expect.any(AbortSignal));
+    });
+
+    it('should abort the signal when transition.ready rejects', async () => {
+      let capturedSignal: AbortSignal | undefined;
+      let resolveUpdate!: () => void;
+      const updateCallbackDone = new Promise<void>((resolve) => {
+        resolveUpdate = resolve;
+      });
+
+      const readyError = new Error('Transition was aborted because of timeout in DOM update');
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return {
+          updateCallbackDone,
+          finished: Promise.reject(readyError),
+          ready: Promise.reject(readyError),
+          skipTransition: vi.fn(),
+        };
+      });
+
+      const performUpdate = vi.fn().mockImplementation((signal: AbortSignal) => {
+        capturedSignal = signal;
+        return new Promise<void>((resolve) => {
+          signal.addEventListener('abort', () => resolve(), { once: true });
+        });
+      });
+
+      const promise = manager.startTransition({ performUpdate });
+
+      // Flush microtasks so ready rejection fires and aborts the signal
+      await new Promise<void>((r) => queueMicrotask(r));
+      await new Promise<void>((r) => queueMicrotask(r));
+
+      expect(capturedSignal?.aborted).toBe(true);
+
+      resolveUpdate();
+      await promise;
+    });
+
+    it('should not abort the signal when transition completes normally', async () => {
+      let capturedSignal: AbortSignal | undefined;
+
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn().mockImplementation((arg: unknown) => {
+        const updateFn = typeof arg === 'function' ? arg : (arg as { update: () => Promise<void> }).update;
+        void updateFn();
+        return {
+          updateCallbackDone: Promise.resolve(),
+          finished: Promise.resolve(),
+          ready: Promise.resolve(),
+          skipTransition: vi.fn(),
+        };
+      });
+
+      await manager.startTransition({
+        performUpdate: (signal) => {
+          capturedSignal = signal;
+          return Promise.resolve();
+        },
+      });
+
+      expect(capturedSignal?.aborted).toBe(false);
+    });
+
+    it('should pass a non-aborted signal in the unsupported fallback path', async () => {
+      let capturedSignal: AbortSignal | undefined;
+
+      await manager.startTransition({
+        performUpdate: (signal) => {
+          capturedSignal = signal;
+          return Promise.resolve();
+        },
+      });
+
+      expect(capturedSignal).toBeInstanceOf(AbortSignal);
+      expect(capturedSignal?.aborted).toBe(false);
+    });
+  });
+
+  describe('isSupported', () => {
+    it('should return false when startViewTransition is not in document', () => {
+      expect(manager.isSupported()).toBe(false);
+    });
+
+    it('should return true when startViewTransition is in document', () => {
+      // eslint-disable-next-line tscompat/tscompat
+      document.startViewTransition = vi.fn();
+
+      expect(manager.isSupported()).toBe(true);
+    });
+  });
+});

web/src/lib/managers/ViewTransitionManager.svelte.ts

@@ -0,0 +1,94 @@
+import { tick } from 'svelte';
+
+interface TransitionRequest {
+  types?: string[];
+  prepareOldSnapshot?: () => void;
+  performUpdate: (signal: AbortSignal) => Promise<void>;
+  prepareNewSnapshot?: () => void;
+  onFinished?: () => void;
+}
+
+export class ViewTransitionManager {
+  #activeViewTransition = $state<ViewTransition | null>(null);
+
+  get activeViewTransition() {
+    return this.#activeViewTransition;
+  }
+
+  isSupported() {
+    return 'startViewTransition' in document;
+  }
+
+  skipTransitions() {
+    const skipped = !!this.#activeViewTransition;
+    this.#activeViewTransition?.skipTransition();
+    this.#activeViewTransition = null;
+    return skipped;
+  }
+
+  async startTransition({
+    types,
+    prepareOldSnapshot,
+    performUpdate,
+    prepareNewSnapshot,
+    onFinished,
+  }: TransitionRequest) {
+    if (this.#activeViewTransition) {
+      return;
+    }
+
+    if (!this.isSupported()) {
+      await performUpdate(AbortSignal.timeout(10_000));
+      onFinished?.();
+      return;
+    }
+
+    prepareOldSnapshot?.();
+    await tick();
+
+    const abortController = new AbortController();
+    let transition: ViewTransition;
+    try {
+      // eslint-disable-next-line tscompat/tscompat
+      transition = document.startViewTransition({
+        update: async () => {
+          await performUpdate(abortController.signal);
+          prepareNewSnapshot?.();
+          await tick();
+        },
+        types,
+      });
+    } catch {
+      // eslint-disable-next-line tscompat/tscompat
+      transition = document.startViewTransition(async () => {
+        await performUpdate(abortController.signal);
+        prepareNewSnapshot?.();
+        await tick();
+      });
+    }
+
+    this.#activeViewTransition = transition;
+
+    // eslint-disable-next-line tscompat/tscompat
+    void transition.ready.catch((error: unknown) => {
+      abortController.abort(error);
+    });
+
+    // Let animation run in the background — don't block the caller.
+    // This allows skipTransitions() to abort mid-animation for rapid navigation.
+    // eslint-disable-next-line tscompat/tscompat
+    void transition.finished
+      .catch(() => {})
+      .finally(() => {
+        this.#activeViewTransition = null;
+        onFinished?.();
+      });
+
+    // Wait only until the DOM update completes (both snapshots captured),
+    // not for the animation to finish.
+    // eslint-disable-next-line tscompat/tscompat
+    await transition.updateCallbackDone;
+  }
+}
+
+export const viewTransitionManager = new ViewTransitionManager();

web/src/lib/managers/app-manager.svelte.ts

@@ -0,0 +1,5 @@
+class AppManager {
+  isAssetViewer = $state(false);
+}
+
+export const appManager = new AppManager();

web/src/lib/managers/event-manager.svelte.ts

@@ -89,6 +89,15 @@ export type Events = {
   ReleaseEvent: [ReleaseEvent];
 
   WebsocketConnect: [];
+
+  TimelineLoaded: [{ id: string | null }];
+  TimelineScrolledToAsset: [{ id: string }];
+
+  ViewerAfterNavigate: [];
+  ViewerCloseTransition: [{ id: string }];
+  ViewerCloseTransitionReady: [];
+  ViewerOpenTransition: [];
+  ViewerOpenTransitionReady: [];
 };
 
 export const eventManager = new BaseEventManager<Events>();

web/src/lib/managers/timeline-manager/utils.svelte.ts

@@ -2,3 +2,11 @@ import type { TimelineAsset } from './types';
 
 export const assetSnapshot = (asset: TimelineAsset): TimelineAsset => $state.snapshot(asset);
 export const assetsSnapshot = (assets: TimelineAsset[]) => assets.map((asset) => $state.snapshot(asset));
+
+export function* filterIntersecting<T extends { intersecting: boolean }>(items: T[]) {
+  for (const item of items) {
+    if (item.intersecting) {
+      yield item;
+    }
+  }
+}

web/src/lib/stores/asset-viewing.store.ts

@@ -5,6 +5,7 @@ import { readonly, writable } from 'svelte/store';
 
 function createAssetViewingStore() {
   const viewingAssetStoreState = writable<AssetResponseDto>();
+  const invisible = writable<boolean>(false);
   const viewState = writable<boolean>(false);
   const gridScrollTarget = writable<AssetGridRouteSearchParams | null | undefined>();
 
@@ -30,6 +31,7 @@ function createAssetViewingStore() {
     setAsset,
     setAssetId,
     showAssetViewer,
+    invisible,
   };
 }
 

web/src/lib/utils/base-event-manager.svelte.ts

@@ -43,6 +43,50 @@ export class BaseEventManager<Events extends EventsBase> {
     };
   }
 
+  once<T extends keyof Events>(event: T, callback: EventCallback<Events, T>) {
+    const unsubscribe = this.#onEvent(event, (...args: Events[T]) => {
+      unsubscribe();
+      return callback(...args);
+    });
+    return unsubscribe;
+  }
+
+  untilNext<T extends keyof Events>(
+    event: T,
+    { timeoutMs = 10_000, signal }: { timeoutMs?: number; signal?: AbortSignal } = {},
+  ): Promise<Events[T] extends [] ? void : Events[T][0]> {
+    type Result = Events[T] extends [] ? void : Events[T][0];
+    return new Promise<Result>((resolve, reject) => {
+      let settled = false;
+      const settle = () => {
+        if (settled) {
+          return false;
+        }
+        settled = true;
+        unsubscribe();
+        clearTimeout(timer);
+        signal?.removeEventListener('abort', onAbort);
+        return true;
+      };
+      const unsubscribe = this.once(event, (...args: Events[T]) => {
+        if (settle()) {
+          resolve(args[0] as Result);
+        }
+      });
+      const timer = setTimeout(() => {
+        if (settle()) {
+          reject(new Error(`untilNext('${String(event)}') timed out after ${timeoutMs}ms`));
+        }
+      }, timeoutMs);
+      const onAbort = () => {
+        if (settle()) {
+          resolve(undefined as Result);
+        }
+      };
+      signal?.addEventListener('abort', onAbort, { once: true });
+    });
+  }
+
   emit<T extends keyof Events>(event: T, ...params: Events[T]) {
     const listeners = this.getListeners(event);
     for (const listener of listeners) {

web/src/lib/utils/invocationTracker.ts

@@ -1,66 +1,36 @@
-import { handleError } from '$lib/utils/handle-error';
-
-/**
- * Tracks the state of asynchronous invocations to handle race conditions and stale operations.
- * This class helps manage concurrent operations by tracking which invocations are active
- * and allowing operations to check if they're still valid.
- */
 export class InvocationTracker {
-  /** Counter for the number of invocations that have been started */
   invocationsStarted = 0;
-  /** Counter for the number of invocations that have been completed */
   invocationsEnded = 0;
 
-  constructor() {}
-
-  /**
-   * Starts a new invocation and returns an object with utilities to manage the invocation lifecycle.
-   * @returns  An object containing methods to manage the invocation:
-   *   - isInvalidInvocationError: Checks if an error is an invalid invocation error
-   *   - checkStillValid: Throws an error if the invocation is no longer valid
-   *   - endInvocation: Marks the invocation as complete
-   */
   startInvocation() {
     this.invocationsStarted++;
     const invocation = this.invocationsStarted;
 
     return {
-      /**
+      isStillValid: () => invocation === this.invocationsStarted,
-       * Throws an error if this invocation is no longer valid
-       * @throws {Error} If the invocation is no longer valid
-       */
-      isStillValid: () => {
-        if (invocation !== this.invocationsStarted) {
-          return false;
-        }
-        return true;
-      },
-
-      /**
-       * Marks this invocation as complete
-       */
       endInvocation: () => {
-        this.invocationsEnded = invocation;
+        this.invocationsEnded = Math.max(this.invocationsEnded, invocation);
       },
     };
   }
 
-  /**
-   * Checks if there are any active invocations
-   * @returns True if there are active invocations, false otherwise
-   */
   isActive() {
     return this.invocationsStarted !== this.invocationsEnded;
   }
 
-  async invoke<T>(invocable: () => Promise<T>, localizedMessage: string) {
+  async invoke<T>(invocable: () => Promise<T>, catchCallback?: (error: unknown) => void, finallyCallback?: () => void) {
     const invocation = this.startInvocation();
     try {
       return await invocable();
     } catch (error: unknown) {
-      handleError(error, localizedMessage);
+      if (catchCallback) {
+        catchCallback(error);
+      } else {
+        console.error(error);
+      }
     } finally {
       invocation.endInvocation();
+      finallyCallback?.();
     }
   }
 }

web/src/lib/utils/transition-utils.ts

@@ -0,0 +1,84 @@
+import { eventManager } from '$lib/managers/event-manager.svelte';
+import { viewTransitionManager } from '$lib/managers/ViewTransitionManager.svelte';
+import { tick } from 'svelte';
+
+export function startViewerTransition(
+  assetId: string,
+  navigate: () => void,
+  setTransitionId: (id: string | null) => void,
+) {
+  void viewTransitionManager.startTransition({
+    types: ['viewer'],
+    prepareOldSnapshot: () => {
+      setTransitionId(assetId);
+    },
+    performUpdate: async (signal) => {
+      setTransitionId(null);
+      const ready = eventManager.untilNext('ViewerOpenTransitionReady', { signal });
+      navigate();
+      await ready;
+      eventManager.emit('ViewerOpenTransition');
+      await tick();
+    },
+  });
+}
+
+let activeOverlay: HTMLElement | undefined;
+
+export function removeCrossfadeOverlay() {
+  if (activeOverlay) {
+    activeOverlay.remove();
+    activeOverlay = undefined;
+  }
+}
+
+export async function crossfadeViewerContent(updateFn: () => void | Promise<void>, duration = 200) {
+  const viewerContent = document.querySelector<HTMLElement>('[data-viewer-content]');
+  if (!viewerContent) {
+    await updateFn();
+    return;
+  }
+
+  removeCrossfadeOverlay();
+
+  const clone = viewerContent.cloneNode(true) as HTMLElement;
+  Object.assign(clone.style, {
+    position: 'absolute',
+    inset: '0',
+    zIndex: '1',
+    pointerEvents: 'none',
+  });
+  delete clone.dataset.viewerContent;
+  if (!viewerContent.parentElement) {
+    await updateFn();
+    return;
+  }
+  viewerContent.parentElement.append(clone);
+  activeOverlay = clone;
+
+  const ready = eventManager.untilNext('ViewerOpenTransitionReady');
+  await updateFn();
+
+  try {
+    await ready;
+  } catch {
+    clone.remove();
+    if (activeOverlay === clone) {
+      activeOverlay = undefined;
+    }
+    return;
+  }
+
+  const fadeOut = clone.animate([{ opacity: 1 }, { opacity: 0 }], {
+    duration,
+    easing: 'cubic-bezier(0.4, 0, 1, 1)',
+    fill: 'forwards',
+  });
+
+  void fadeOut.finished.then(() => {
+    clone.remove();
+    if (activeOverlay === clone) {
+      activeOverlay = undefined;
+    }
+  });
+}

web/src/routes/(user)/+layout.svelte

@@ -24,7 +24,7 @@
   });
 </script>
 
-<div class:display-none={$showAssetViewer}>
+<div class:invisible={$showAssetViewer}>
   {@render children?.()}
 </div>
 <UploadCover />
@@ -33,7 +33,4 @@
   :root {
     overscroll-behavior: none;
   }
-  .display-none {
-    display: none;
-  }
 </style>

web/src/routes/(user)/map/[[photos=photos]]/[[assetId=id]]/+page.svelte

@@ -6,13 +6,16 @@
   import { timeToLoadTheMap } from '$lib/constants';
   import Portal from '$lib/elements/Portal.svelte';
   import { featureFlagsManager } from '$lib/managers/feature-flags-manager.svelte';
+  import { viewTransitionManager } from '$lib/managers/ViewTransitionManager.svelte';
   import { Route } from '$lib/route';
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
   import { handlePromiseError } from '$lib/utils';
   import { delay } from '$lib/utils/asset-utils';
   import { navigate } from '$lib/utils/navigation';
   import { LoadingSpinner } from '@immich/ui';
+  import { linear } from 'svelte/easing';
   import { onDestroy } from 'svelte';
+  import { fly } from 'svelte/transition';
   import type { PageData } from './$types';
 
   interface Props {
@@ -41,9 +44,14 @@
     handlePromiseError(goto(Route.photos()));
   }
 
-  async function onViewAssets(assetIds: string[]) {
+  function onViewAssets(assetIds: string[]) {
-    await setAssetId(assetIds[0]);
+    void viewTransitionManager.startTransition({
-    closeTimelinePanel();
+      types: ['viewer'],
+      performUpdate: async () => {
+        await setAssetId(assetIds[0]);
+        closeTimelinePanel();
+      },
+    });
   }
 
   function onClusterSelect(assetIds: string[], bbox: SelectionBBox) {
@@ -77,7 +85,10 @@
       </div>
 
       {#if isTimelinePanelVisible && selectedClusterBBox}
-        <div class="h-1/2 min-h-0 w-full pt-2 sm:h-full sm:w-1/3 sm:ps-2 sm:pt-0">
+        <div
+          transition:fly={{ x: 400, duration: 150, easing: linear }}
+          class="h-1/2 min-h-0 w-full pt-2 sm:h-full sm:w-1/3 sm:ps-2 sm:pt-0"
+        >
           <MapTimelinePanel
             bbox={selectedClusterBBox}
             {selectedClusterIds}
@@ -89,7 +100,7 @@
     </div>
   </UserPageLayout>
   <Portal target="body">
-    {#if $showAssetViewer}
+    {#if $showAssetViewer && !isTimelinePanelVisible}
       {#await import('$lib/components/asset-viewer/asset-viewer.svelte') then { default: AssetViewer }}
         <AssetViewer
           cursor={{ current: $viewingAsset }}

web/src/routes/+layout.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { afterNavigate, beforeNavigate, goto } from '$app/navigation';
+  import { afterNavigate, beforeNavigate, goto, onNavigate } from '$app/navigation';
   import { page } from '$app/state';
   import { shortcut } from '$lib/actions/shortcut';
   import DownloadPanel from '$lib/components/asset-viewer/download-panel.svelte';
@@ -8,6 +8,7 @@
   import NavigationLoadingBar from '$lib/components/shared-components/navigation-loading-bar.svelte';
   import UploadPanel from '$lib/components/shared-components/upload-panel.svelte';
   import VersionAnnouncement from '$lib/components/VersionAnnouncement.svelte';
+  import { appManager } from '$lib/managers/app-manager.svelte';
   import { eventManager } from '$lib/managers/event-manager.svelte';
   import { serverConfigManager } from '$lib/managers/server-config-manager.svelte';
   import { themeManager } from '$lib/managers/theme-manager.svelte';
@@ -77,6 +78,8 @@
 
   let showNavigationLoadingBar = $state(false);
 
+  appManager.isAssetViewer = isAssetViewerRoute(page);
+
   const getMyImmichLink = () => {
     return new URL(page.url.pathname + page.url.search, 'https://my.immich.app');
   };
@@ -102,8 +105,15 @@
     showNavigationLoadingBar = true;
   });
 
-  afterNavigate(() => {
+  onNavigate(({ to }) => {
-    showNavigationLoadingBar = false;
+    appManager.isAssetViewer = isAssetViewerRoute(to);
+  });
+
+  afterNavigate(({ to, complete }) => {
+    appManager.isAssetViewer = isAssetViewerRoute(to);
+    void complete.finally(() => {
+      showNavigationLoadingBar = false;
+    });
   });
 
   const { serverRestarting } = websocketStore;