Sleep Tab Hibernator от Aj Gaht

Your Tab Hibernator extension is ready. Here's how to install it in Firefox:
Installation steps:

Download the .zip file above
Open Firefox and go to about:debugging
Click "This Firefox" in the left sidebar
Click "Load Temporary Add-on..."
Navigate to the downloaded zip and select it (Firefox accepts zips directly)

For a permanent install across restarts, you'd need to sign it via addons.mozilla.org — the temporary method works great for personal use.

What it does:

💤 Auto-sleeps inactive tabs after a configurable timeout (5 min → 2 hours)
🔢 Badge counter on the toolbar icon shows how many tabs are currently sleeping
⚡ Sleep All / Wake All buttons for instant control
📌 Smart exclusions — pinned tabs and audio-playing tabs are protected by default (toggleable)
🚫 Whitelist — add any domain (e.g. github.com) to never sleep those tabs
Tabs wake instantly when you click on them