diff --git a/frontend/src/lib/activity/DashboardActivityFeed.svelte.test.ts b/frontend/src/lib/activity/DashboardActivityFeed.svelte.test.ts
new file mode 100644
index 00000000..a0e7fbfc
--- /dev/null
+++ b/frontend/src/lib/activity/DashboardActivityFeed.svelte.test.ts
@@ -0,0 +1,161 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import { page } from 'vitest/browser';
+import DashboardActivityFeed from './DashboardActivityFeed.svelte';
+import type { components } from '$lib/generated/api';
+
+type ActivityFeedItemDTO = components['schemas']['ActivityFeedItemDTO'];
+
+afterEach(cleanup);
+
+const baseItem = (overrides: Partial<ActivityFeedItemDTO> = {}): ActivityFeedItemDTO =>
+	({
+		kind: 'TEXT_SAVED',
+		documentId: 'doc-1',
+		documentTitle: 'Brief 1899',
+		actor: {
+			id: 'u-1',
+			name: 'Anna Schmidt',
+			initials: 'AS',
+			color: '#336699'
+		},
+		count: 1,
+		happenedAt: '2026-04-14T14:02:00Z',
+		happenedAtUntil: null,
+		youMentioned: false,
+		...overrides
+	}) as ActivityFeedItemDTO;
+
+describe('DashboardActivityFeed', () => {
+	it('renders the feed caption and show-all link', async () => {
+		render(DashboardActivityFeed, { props: { feed: [] } });
+
+		await expect.element(page.getByText('Kommentare & Aktivität')).toBeVisible();
+		const link = document.querySelector('a[href="/aktivitaeten"]');
+		expect(link).not.toBeNull();
+	});
+
+	it('renders nothing in the list when the feed is empty', async () => {
+		render(DashboardActivityFeed, { props: { feed: [] } });
+
+		const lists = document.querySelectorAll('ul');
+		expect(lists.length).toBe(0);
+	});
+
+	it('renders one row per feed item with the actor initials', async () => {
+		render(DashboardActivityFeed, {
+			props: {
+				feed: [baseItem(), baseItem({ documentId: 'doc-2', documentTitle: 'Brief 1900' })]
+			}
+		});
+
+		const items = document.querySelectorAll('li');
+		expect(items.length).toBe(2);
+		expect(document.body.textContent).toContain('AS');
+	});
+
+	it('renders the question-mark badge when no actor is set', async () => {
+		render(DashboardActivityFeed, {
+			props: { feed: [baseItem({ actor: null as unknown as undefined })] }
+		});
+
+		const li = document.querySelector('li');
+		expect(li?.textContent).toContain('?');
+	});
+
+	it('renders the rollup count badge when count > 1', async () => {
+		render(DashboardActivityFeed, {
+			props: { feed: [baseItem({ count: 5 })] }
+		});
+
+		const badge = document.querySelector('[data-testid="feed-rollup-count"]');
+		expect(badge?.textContent?.trim()).toBe('5');
+	});
+
+	it('omits the rollup count badge when count is 1', async () => {
+		render(DashboardActivityFeed, { props: { feed: [baseItem({ count: 1 })] } });
+
+		const badge = document.querySelector('[data-testid="feed-rollup-count"]');
+		expect(badge).toBeNull();
+	});
+
+	it('renders the "für dich" badge when youMentioned is true', async () => {
+		render(DashboardActivityFeed, {
+			props: { feed: [baseItem({ youMentioned: true })] }
+		});
+
+		await expect.element(page.getByText(/für dich/i)).toBeVisible();
+	});
+
+	it('maps the kind enum to a localized verb (TEXT_SAVED)', async () => {
+		render(DashboardActivityFeed, {
+			props: { feed: [baseItem({ kind: 'TEXT_SAVED' as ActivityFeedItemDTO['kind'] })] }
+		});
+
+		expect(document.body.textContent).toContain('hat Text gespeichert in');
+	});
+
+	it('maps the kind enum to a localized verb (FILE_UPLOADED)', async () => {
+		render(DashboardActivityFeed, {
+			props: { feed: [baseItem({ kind: 'FILE_UPLOADED' as ActivityFeedItemDTO['kind'] })] }
+		});
+
+		expect(document.body.textContent).toContain('hat eine Datei hochgeladen');
+	});
+
+	it('falls back to the raw kind when no verb is mapped', async () => {
+		render(DashboardActivityFeed, {
+			props: {
+				feed: [baseItem({ kind: 'UNKNOWN_KIND' as unknown as ActivityFeedItemDTO['kind'] })]
+			}
+		});
+
+		expect(document.body.textContent).toContain('UNKNOWN_KIND');
+	});
+
+	it('renders a rollup time range when happenedAtUntil is set and count > 1', async () => {
+		render(DashboardActivityFeed, {
+			props: {
+				feed: [
+					baseItem({
+						happenedAt: '2026-04-14T14:02:00Z',
+						happenedAtUntil: '2026-04-14T14:32:00Z',
+						count: 3
+					})
+				]
+			}
+		});
+
+		// "14:02–14:32" appears (with the en-dash)
+		expect(document.body.textContent).toMatch(/\d{2}:\d{2}–\d{2}:\d{2}/);
+	});
+
+	it('uses the actor initials as the fallback name when name is null', async () => {
+		render(DashboardActivityFeed, {
+			props: {
+				feed: [
+					baseItem({
+						actor: {
+							id: 'u-2',
+							name: null as unknown as undefined,
+							initials: 'XR',
+							color: '#000'
+						}
+					})
+				]
+			}
+		});
+
+		const strong = document.querySelector('strong');
+		expect(strong?.textContent).toBe('XR');
+	});
+
+	it('builds the document detail href from documentId', async () => {
+		render(DashboardActivityFeed, {
+			props: { feed: [baseItem({ documentId: 'doc-xyz', documentTitle: 'Brief 1901' })] }
+		});
+
+		const link = document.querySelector('a[href="/documents/doc-xyz"]');
+		expect(link).not.toBeNull();
+	});
+});