Automatically close old tabs after a configurable time — like Arc Browser. Pinned tabs and essentials are safely put to sleep instead of being closed. Works across all workspaces in Zen Browser.

• 🗑️ Auto-close normal tabs after a configurable delay (1 min → 24h)
• 💤 Sleep pinned/essential tabs — unloaded from memory but stay in your tab bar
• 🛡️ Never touch active or audio tabs — your current tab is always safe
• 🌐 All workspaces — works across every Zen Browser workspace
• ⏱️ Persistent timers — survive browser restarts and sleep/wake
• 🚫 Domain exclusions — exclude specific sites from auto-closing
• 📊 Live statistics — see tab counts update in real-time
• ⚡ Auto-save settings — every change applies instantly

From Firefox Add-ons:

1. Install from addons.mozilla.org
2. Click the FFTabClose icon in the toolbar to configure

From source (development):

1. Clone this repo
2. Go to about:debugging → "This Firefox" / "This Zen"
3. Click "Load Temporary Add-on..." → select manifest.json

Click the extension icon to configure:

• Timer: 1 min (test) to 24 hours, or custom
• Sleep pinned tabs: Discard pinned/essential tabs instead of closing
• Protect audio tabs: Never touch tabs playing sound
• Domain exclusions: Sites to never close (one per line)
• Force process: Immediately run a cleanup cycle

1. Every tab gets a lastActiveAt timestamp when you visit it
2. A background alarm runs every minute to check for old tabs
3. Tabs older than the configured delay are processed:
   • Normal tabs → closed
   • Pinned tabs → discarded (unloaded from memory)
4. Active tabs, audio tabs, and excluded domains are always protected
5. Safety: max 3 tabs closed per cycle if >50% would be affected

FFTabClose is specifically optimized for Zen Browser:

• Cross-workspace: Tracks tabs across ALL workspaces via events, since browser.tabs.query() only returns the active workspace
• Essentials = Pinned: Zen's essential tabs are pinned tabs under the hood — they're automatically protected
• Hidden tabs: Tabs in inactive workspaces are verified with browser.tabs.get() instead of being deleted
• Auto-detection: Extension detects Zen Browser automatically

• Manifest V2 — compatible with Firefox 109+ and Zen Browser
• Persistent background script — timers survive restarts
• browser.tabs.discard() — native Firefox API for clean memory unloading
• browser.alarms — reliable timer that works through sleep/wake
• URL-based timer recovery — timestamps survive browser restarts even when tab IDs change
• No data collection — everything stays local, no network requests

• No data collected — zero telemetry, zero analytics
• No network requests — works entirely offline
• No tab content access — only uses metadata (title, URL)
• Open source — all code available for review

• V5.2: Zen Browser compatibility fix, toggle fix, auto-save, live stats, safety cap
• V5.0: Complete rewrite — browser.tabs.discard(), global processing, domain exclusions
• V4.x: Legacy (broken sleep mechanism, single workspace)

MIT License

Compatible with Firefox & Zen Browser 🎉