diff --git a/src/renderer/components/ActivityBar/ActivityBar.tsx b/src/renderer/components/ActivityBar/ActivityBar.tsx
index 4effda6..425bc6e 100644
--- a/src/renderer/components/ActivityBar/ActivityBar.tsx
+++ b/src/renderer/components/ActivityBar/ActivityBar.tsx
@@ -66,8 +66,8 @@ export const ActivityBar: React.FC = () => {
   // Check if settings view is active (either tab or sidebar)
   const isSettingsActive = (activeView === 'settings' && sidebarVisible) || isSettingsTabActive;
   
-  // Check if tags tab is currently active
-  const isTagsTabActive = tabs.some(t => t.type === 'tags' && t.id === activeTabId);
+  // Check if tags sidebar is active
+  const isTagsActive = activeView === 'tags' && sidebarVisible;
 
   // Check if chat sidebar is active (activeView === 'chat' and sidebar is visible)
   const isChatActive = activeView === 'chat' && sidebarVisible;
@@ -108,8 +108,16 @@ export const ActivityBar: React.FC = () => {
   };
 
   const handleTagsClick = () => {
-    // Open tags as a dedicated (non-transient) tab
-    openTab({ type: 'tags', id: 'tags', isTransient: false });
+    // Toggle sidebar if tags is already active, otherwise switch to tags
+    if (activeView === 'tags' && sidebarVisible) {
+      toggleSidebar();
+    } else {
+      openTab({ type: 'tags', id: 'tags', isTransient: false });
+      setActiveView('tags');
+      if (!sidebarVisible) {
+        toggleSidebar();
+      }
+    }
   };
 
   const handleImportClick = () => {
@@ -148,9 +156,9 @@ export const ActivityBar: React.FC = () => {
           <MediaIcon />
         </button>
         <button
-          className={`activity-bar-item ${isTagsTabActive ? 'active' : ''}`}
+          className={`activity-bar-item ${isTagsActive ? 'active' : ''}`}
           onClick={handleTagsClick}
-          title={t('activity.tags')}
+          title={`${t('activity.tags')} ${t('activity.toggleHint')}`}
         >
           <TagsIcon />
         </button>
diff --git a/src/renderer/components/Sidebar/Sidebar.tsx b/src/renderer/components/Sidebar/Sidebar.tsx
index efec9cc..1b48ce0 100644
--- a/src/renderer/components/Sidebar/Sidebar.tsx
+++ b/src/renderer/components/Sidebar/Sidebar.tsx
@@ -1223,11 +1223,19 @@ import { scrollToTagsSection, TagsCategory } from '../TagsView';
 
 const TagsNav: React.FC = () => {
   const { t } = useI18n();
+  const { tabs, activeTabId, openTab } = useAppStore();
   const [activeSection, setActiveSection] = useState<TagsCategory | null>(null);
 
+  const isTagsTabActive = tabs.some(t => t.type === 'tags' && t.id === activeTabId);
+
   const handleNavClick = (category: TagsCategory) => {
+    if (!isTagsTabActive) {
+      openTab({ type: 'tags', id: 'tags', isTransient: false });
+    }
     setActiveSection(category);
-    scrollToTagsSection(category);
+    setTimeout(() => {
+      scrollToTagsSection(category);
+    }, isTagsTabActive ? 0 : 100);
   };
 
   return (
diff --git a/tests/renderer/components/ActivityBar.test.tsx b/tests/renderer/components/ActivityBar.test.tsx
new file mode 100644
index 0000000..b70ee9a
--- /dev/null
+++ b/tests/renderer/components/ActivityBar.test.tsx
@@ -0,0 +1,98 @@
+import React from 'react';
+import { beforeEach, describe, expect, it } from 'vitest';
+import { fireEvent, render, screen } from '@testing-library/react';
+import { ActivityBar } from '../../../src/renderer/components/ActivityBar/ActivityBar';
+import { I18nProvider } from '../../../src/renderer/i18n';
+import { useAppStore } from '../../../src/renderer/store';
+
+describe('ActivityBar tags behavior', () => {
+  beforeEach(() => {
+    useAppStore.setState({
+      activeView: 'posts',
+      sidebarVisible: true,
+      tabs: [],
+      activeTabId: null,
+    });
+  });
+
+  it('opens tags tab and switches sidebar to tags view when clicking Tags', () => {
+    render(
+      <I18nProvider>
+        <ActivityBar />
+      </I18nProvider>
+    );
+
+    fireEvent.click(screen.getByTitle('Tags (click again to toggle sidebar)'));
+
+    const state = useAppStore.getState();
+    expect(state.activeView).toBe('tags');
+    expect(state.sidebarVisible).toBe(true);
+    expect(state.activeTabId).toBe('tags');
+    expect(state.tabs).toContainEqual({ type: 'tags', id: 'tags', isTransient: false });
+  });
+
+  it('toggles tags sidebar off when tags view is already active', () => {
+    useAppStore.setState({
+      activeView: 'tags',
+      sidebarVisible: true,
+      tabs: [{ type: 'tags', id: 'tags', isTransient: false }],
+      activeTabId: 'tags',
+    });
+
+    render(
+      <I18nProvider>
+        <ActivityBar />
+      </I18nProvider>
+    );
+
+    fireEvent.click(screen.getByTitle('Tags (click again to toggle sidebar)'));
+
+    expect(useAppStore.getState().sidebarVisible).toBe(false);
+  });
+
+  it('shows tags sidebar when hidden and tags view is active', () => {
+    useAppStore.setState({
+      activeView: 'tags',
+      sidebarVisible: false,
+      tabs: [{ type: 'tags', id: 'tags', isTransient: false }],
+      activeTabId: 'tags',
+    });
+
+    render(
+      <I18nProvider>
+        <ActivityBar />
+      </I18nProvider>
+    );
+
+    fireEvent.click(screen.getByTitle('Tags (click again to toggle sidebar)'));
+
+    expect(useAppStore.getState().sidebarVisible).toBe(true);
+  });
+
+  it('does not mark tags icon active when tags editor tab is open but another sidebar is active', () => {
+    useAppStore.setState({
+      activeView: 'posts',
+      sidebarVisible: true,
+      tabs: [{ type: 'tags', id: 'tags', isTransient: false }],
+      activeTabId: 'tags',
+    });
+
+    render(
+      <I18nProvider>
+        <ActivityBar />
+      </I18nProvider>
+    );
+
+    expect(screen.getByTitle('Tags (click again to toggle sidebar)')).not.toHaveClass('active');
+  });
+
+  it('uses the shared toggle hint in the tags activity button title', () => {
+    render(
+      <I18nProvider>
+        <ActivityBar />
+      </I18nProvider>
+    );
+
+    expect(screen.getByTitle('Tags (click again to toggle sidebar)')).toBeInTheDocument();
+  });
+});