Thread — AI Tab Groups per Smit Patel

Thread uses AI on your device to organize related tabs into Firefox's built-in tab groups and give each new group a name. Click its toolbar button to organize the current window. Tabs without a clear match stay ungrouped.

Your existing groups guide new matches. Their names, colors and existing members stay intact.

Changing groups

If you don't want a group Thread created, use Reject to ungroup its tabs in place without closing them. Reject is available only for unchanged groups without protected tabs. Your other groups stay as they are. Click Organize ungrouped tabs when you're ready to try again.

Thread remembers up to 50 rejected combinations per window locally, using opaque tab IDs. It won't put that whole combination back together, even inside a larger group. Smaller or different groups are still possible. Closing a member or manually regrouping the members clears that feedback when Thread next checks.

Choose More focused, Balanced or Broader for new groups. A different style may still give the same result. Undo reverses the latest organization where safe, leaving later manual changes alone. You can also move tabs and rename groups with Firefox's own controls. Click a group in Thread's list to return to its most recently used open tab.

Thread leaves pinned, hidden, playing or sharing tabs alone and keeps containers separate. It doesn't run in private windows, close tabs automatically, or rearrange them in the background.

Grouping and naming aren't always right. English titles work best.

AI and privacy

AI compares tab titles and minimized address information to find related topics. Group names are processed locally too. Thread doesn't read page contents, cookies or closed browsing history. You don't need an account or API key, and there's no cloud inference, advertising or Thread analytics.

The first run may download about 85 MB of model files from Hugging Face and Mozilla. Those hosts receive file requests and normal connection information, not your browsing inputs. Firefox may download extra runtime components. Once the files are cached, inference runs locally.

Firefox's native AI runtime is optional, with permission requested separately from model-download access. If you decline it, or the runtime isn't available, Thread uses its bundled local runtime. You don't need Nightly or changed AI flags. The runtimes cache models separately, so switching may mean another download. Firefox's runtime follows Firefox's diagnostic settings; Thread doesn't change them.

Canceling stops native AI results from changing tabs, though a native download or computation already in progress may finish.

Activity learning is off by default. If you turn it on, it keeps up to 500 local tab connections for up to seven days. Group corrections, rejection feedback and Undo work separately from that setting.

Requires desktop Firefox 140 or newer with native tab groups. Android isn't supported. Thread is an independent, open-source extension and isn't made by Mozilla.

Source code: https://github.com/smitp/thread-tab-group
Support: https://github.com/smitp/thread-tab-group/issues
Issues are public. Please leave out private browsing data and credentials.