Firefox launches Sidebar option and here is How to Enable Vertical Tabs in Firefox

Mozilla Firefox launches sidebar option and here is what you can do with it.

Firefox Sidebar Major Features:

1. Vertical Tabs in Sidebar
   • Move tabs to a vertical layout in the sidebar, reducing horizontal clutter and improving focus.
2. Pin Key Sites
   • Pin frequently used websites for instant access directly from the sidebar.
3. Integrated AI Assistant
   • Keep the AI assistant readily accessible within the sidebar for quick interactions.
4. Enhanced Sidebar Design
   • A redesigned sidebar consolidates tools (tabs, pinned sites, AI) for streamlined navigation.

Key Benefits of Firefox Sidebar:

• Reduced visual clutter.
• Faster access to essential tools and websites.
• Improved multitasking with a cleaner interface.

How to enable vertical tabs and the new sidebar in Mozilla Firefox?

For Firefox 136 or Newer (Stable Release)

1. Enable Vertical Tabs
   • Right-click an empty space on the tab bar (top of the browser).
   • Select Turn on Vertical Tabs from the context menu.
   • Tabs will instantly switch to a vertical layout on the left (or right) side.
2. Enable/Adjust the Sidebar
   • Click the Menu button (☰) > Settings > General.
   • Under Browser Layout, toggle Show Sidebar .
   • Customize the sidebar tools (AI chatbot, bookmarks, history) via the gear icon at the bottom of the sidebar.
3. Customize Placement
   • Drag the sidebar edge to resize it.
   • Move the sidebar to the right by clicking the gear icon > Sidebar Position

For Firefox Nightly (Experimental Build)

1. Update to the Latest Nightly Version
   • Ensure you’re on Nightly 131 or newer.
2. Activate Experiments
   • Go to Settings > Firefox Labs.
   • Enable Sidebar and Vertical Tabs experiments.
3. Add Sidebar to Toolbar
   • Right-click the toolbar > Customize Toolbar.
   • Drag the Sidebar icon to your toolbar for quick access

Advanced Configuration (Optional)

• Auto-Hide Tabs/Sidebar: Use userChrome.css hacks to auto-collapse the sidebar or hide the horizontal tab bar (requires enabling toolkit.legacyUserProfileCustomizations.stylesheets in about:config).
• Resize Sidebar: Adjust the width by dragging the divider between the sidebar and main window.
• Keyboard Shortcuts: Use Ctrl+Z (Windows/Linux) or Cmd+Z (macOS) to toggle between collapsed and expanded views

Troubleshooting

• If the options aren’t visible, ensure your Firefox is updated to version 136+ (released March 2025).
• For older versions (e.g., 129–135), enable vertical tabs manually via about:config by setting sidebar.revamp and sidebar.verticalTabs to true 

FAQs: Activating Vertical Tabs & Sidebar in Firefox

Q1: How do I enable vertical tabs in Firefox?

1. Right-click the horizontal tab bar at the top of Firefox.
2. Select “Turn on Vertical Tabs” from the menu.
3. Tabs will shift to a vertical layout on the left/right side.

Q2: How do I access the new Firefox sidebar?

• Go to ☰ Menu > Settings > General > Browser Layout.
• Toggle “Show Sidebar” to enable it.
• Customize the sidebar via the gear icon at its bottom.

Q3: Why don’t I see the vertical tabs option in Firefox?

• Ensure you’re using Firefox 136 or newer (released March 2025).
• If outdated, update via ☰ Menu > Help > About Firefox.
• For older versions, enable via about:config (search sidebar.verticalTabs).

Q4: Can I use vertical tabs on Firefox Nightly?

Yes!

1. Update to Nightly 131+.
2. Go to Settings > Firefox Labs.
3. Enable “Sidebar” and “Vertical Tabs” experiments.

Q5: How do I pin websites to the Firefox sidebar?

1. Open the site you want to pin.
2. Right-click its tab and select “Pin Tab”.
3. Pinned sites will stay visible in the sidebar.

Q6: How do I use the AI assistant in Firefox’s sidebar?

1. Enable the sidebar (see Q2).
2. Click the AI Assistant icon (e.g., ChatGPT or Firefox’s built-in tool).
3. Type prompts directly in the sidebar panel.

Q7: How do I move the sidebar to the right in Firefox?

• Click the gear icon at the bottom of the sidebar.
• Select “Sidebar Position > Right”.

Q8: Are there keyboard shortcuts for vertical tabs?

• Toggle sidebar: Ctrl+Z (Windows/Linux) or Cmd+Z (macOS).
• Collapse sidebar: Click the arrow icon at the top.

Q9: How do I revert to horizontal tabs in Firefox?

• Right-click the vertical tab bar > “Turn off Vertical Tabs”.
• Alternatively, disable the sidebar via Settings > General.

Q10: Does Firefox’s vertical tabs work on mobile?

No, vertical tabs and the sidebar are currently desktop-only features (Windows, macOS, Linux).

Q11: Can I auto-hide the vertical tab bar?

Yes, with advanced tweaks:

1. Enable toolkit.legacyUserProfileCustomizations.stylesheets in about:config.
2. Add CSS rules via userChrome.css to auto-collapse the sidebar.

Q12: What are the system requirements for vertical tabs?

• OS: Windows 10+, macOS 12+, or Linux.
• Firefox version: 136+ (Stable) or Nightly 131+.

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