Tab Observatory by Jal

Got hundreds—or thousands—of Firefox tabs?
Tab Observatory gives you a searchable command center for understanding the pile before you clean it up.

See the whole collection:

• Group open tabs by site/domain.
• Search titles, URLs, sites, and Collections.
• Sort by when you last accessed a tab.
• Filter by age, sleeping/loaded state, site, or Collection.
• See how many tabs have gone untouched for months or years.

Find duplicate tabs: Tab Observatory detects exact duplicates and likely same-page URL variants, then shows duplicate copies together with their individual last-accessed times and Firefox locations.

Organize without reorganizing Firefox: Create lightweight Collections such as "Guitar", "Articles to read", or "Research". Collections are labels: they do not move or hide your Firefox tabs, and a page can belong to more than one Collection.

Clean up without losing everything: "Archive & Close" saves a page's title, URL, site, last-access information, and Collections into Tab Observatory's local Archive before closing its Firefox tab.

You can later search the Archive and restore a page. If you simply want something gone, Close without archiving is available too. Destructive actions require confirmation, and pinned tabs receive an explicit warning.

Built for large sessions: Tab Observatory was developed and tested against a real Firefox session with more than 800 open tabs. Sleeping/discarded tabs are inventoried without being woken just because you opened the dashboard.

Lightweight by design: Tab Observatory uses only the tabs and storage permissions, has no host permissions, makes no network requests, and never reads webpage contents.

Local-first by design: Tab Observatory asks only for Firefox's tabs and storage permissions.

It has:

• no host permissions;
• no content scripts;
• no analytics;
• no network requests;
• no account or cloud service.

Your Archive, Collections, preferences, and observation history stay in Firefox's local extension storage. You can create and restore portable JSON backups whenever you want, with the option to include a point-in-time inventory of all currently open tabs.

Tab Observatory does not try to replace Firefox's tab bar, force tabs into workspaces, or automatically reorganize your browser. It simply makes a very large tab collection understandable and manageable.