TabKeeper — Firefox Extension

TabKeeper is a Firefox tab and session manager heavily inspired by Session Buddy, a popular Chrome extension. It is an independent, unofficial project — not affiliated with, endorsed by, or a port of Session Buddy or its authors.

It brings similar session management ideas to Firefox, with additional features like private window cookie management, session history, drag-and-drop organization, and full keyboard navigation.

Features

Sessions (Collections)

• Save all open windows and tabs as a named collection
• Save only the current window
• Restore a collection in a new window or replace the current window
• Rename, duplicate, and delete collections (F2 / Delete keyboard shortcuts)
• Replace a collection with the current browser state
• Tab groups are saved and restored with their original colors and titles
• Drag and drop tabs and windows within a collection to reorganize
• Drag collections together in the sidebar to merge them

Tab Selection

• Click any tab row to select it; Shift-click or Shift-Arrow to range-select
• Arrow Up / Down to navigate; Space / Enter to toggle selection
• Select tabs across multiple windows, then:
  • Save them as a new collection
  • Extract them to a new window within the collection
  • Copy their URLs to the clipboard
  • Remove them from the session

History

• Automatically saves a snapshot when the browser closes
• Auto-saves every 5 minutes
• Timeline grouped by date — click any entry to browse its tabs
• Save any history entry as a permanent collection
• Open a history entry in a new window
• Delete individual entries or clear all history
• Keeps the last 50 entries

Export / Import

• Export a collection as JSON (full fidelity, re-importable)
• Export as indented plain text (human-readable)
• Import JSON or text files; both formats support multiple sessions per file
• Save dialog shown for both formats

Private Window Cookie Manager

• Save all cookies from private windows to a JSON file
• Optionally include the URLs of open private tabs in the export
• Restore cookies and tabs into an already-open private window
• Clear all private cookies, or clear by domain
• Browse current private cookies grouped by domain

Keyboard Shortcuts

Key	Action
F2	Rename current collection
Delete	Delete current collection / remove selected tabs
Escape	Close modal / clear selection
↑ / ↓	Navigate tab list
Shift + ↑ / ↓	Extend tab selection
Space / Enter	Toggle selection on focused tab
← / → (in modal)	Move focus between buttons
Enter (in modal input)	Confirm action

Installation (Developer Mode)

1. Open about:debugging#/runtime/this-firefox in Firefox
2. Click Load Temporary Add-on…
3. Select manifest.json from this folder

For private window cookie support, go to about:addons → TabKeeper → Allow in private windows.

Local file tab support (file:// URLs)

Firefox restricts extensions from opening file:// URLs by default. To enable it, add the following to your Firefox profile's user.js file (create it if it doesn't exist, next to prefs.js in your profile folder):

user_pref("capability.policy.policynames", "localfilelinks");
user_pref("capability.policy.localfilelinks.sites", "moz-extension://YOUR-EXTENSION-UUID");
user_pref("capability.policy.localfilelinks.checkloaduri.enabled", "allAccess");

Replace YOUR-EXTENSION-UUID with the internal UUID shown at about:debugging#/runtime/this-firefox next to TabKeeper (it looks like xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, not the @ ID from the manifest). Restart Firefox after saving user.js.

Without this setting, sessions containing file:// tabs will open a placeholder page instead — you can still open them manually from there.

Requirements

• Firefox 109 or later
• Firefox 136+ required for tab group support
• No build step — plain HTML, CSS, and vanilla JS

File Structure

session-buddy/
├── manifest.json           Extension manifest (MV3)
├── background.js           Background page — IndexedDB, session capture, history
├── icons/
│   ├── icon-16.svg
│   ├── icon-48.svg
│   └── icon-128.svg
├── placeholder/
│   ├── index.html          Shown when a tab URL can't be restored directly
│   └── placeholder.js
└── manager/
    ├── manager.html        Main UI page
    ├── manager.css         Dark theme styles
    ├── manager.js          UI logic — views, selection, import/export
    └── drag-drop.js        Drag-and-drop for tabs, windows, and collections

Permissions

Permission	Reason
tabs	Read tab URLs, titles, and group IDs
tabGroups	Read and restore tab group colors and titles
storage / unlimitedStorage	Persist sessions and history in IndexedDB
downloads	Show save-as dialog when exporting files
alarms	Periodic history auto-save every 5 minutes
cookies	Read and write private window cookies
<all_urls>	Required to access cookies for any domain

Inspiration

TabKeeper takes its core concept from Session Buddy by Shreeram Srinivasan — an excellent Chrome extension for session management. TabKeeper is an independent Firefox implementation and is not affiliated with or endorsed by the Session Buddy project in any way.