Tab Groups Sync & Restore

Firefox syncs your open tabs between devices, but not the groups they belong to. Tab Groups Sync & Restore fills that gap, and lets you decide where your data goes.

You choose where it is stored. Four destinations, each with its own settings, so you can switch between them and switch back without setting anything up twice:

• Firefox Sync — no setup at all. Uses your existing Mozilla account. Fine for a handful of groups; the space Firefox allows extensions is limited, so history is not available here.
• Nextcloud or ownCloud — sign in through your own server. Your password is never stored: the extension asks the server for an app password you can revoke at any time.
• Any WebDAV server — Synology, kDrive, Fastmail, a plain Apache. Give it the address and a login.
• A Git host or your own endpoint — GitHub, Gitea or Forgejo, or a small JSON API you run yourself. The reference implementation is under a hundred lines and is documented.

Nothing happens behind your back. When another computer changes something, the toolbar icon says so and the popup offers three answers:

• Open here — add its groups to the ones you already have open.
• Replace mine — close what is open here and take that computer's session instead.
• Do nothing — dismiss the notice. You will only be asked again when that computer changes something new.

Optional encryption. Choose a master password and your tab titles and addresses are sealed on your computer before they are uploaded. Whoever runs the server sees only unreadable files. You type the password once on each computer. It is never transmitted and cannot be recovered.

History. On the server destinations, a snapshot is kept each time your groups change, per computer. Close a group by mistake and you can bring it back — including from another computer's history. Firefox's own list of recently closed tabs is in the popup too, which covers tabs that were not in a group.

What is not synced. Tabs outside a group stay on the computer they are open on. That gives you a scratch space that never leaves the machine, and it is why a restore never closes them. Private windows are ignored entirely.

Restored tabs are opened unloaded, so bringing back a session of fifty tabs does not fetch fifty pages.

Available in English and Italian. Free software under the GNU GPL v3; the source code and the self-hosting guide are linked below.