Firefox Release Data has facilities for aggregating and exposing information about Firefox releases performed from Mercurial changesets.


This feature is currently experimental and implementation details may change. If you would like the feature to stabilize, please ping gps in #vcs on

This feature is currently only enabled on the mozilla-central repository.


Release Info on Changeset Pages

Changeset pages like display information on Firefox releases in relation to that changeset.

Most pages should have a first release with and last release without section. Exceptions include changesets in the very early and very modern repository history. (This info isn’t displayed unless we can find a release in both directions.)

If a release was made from that changeset, there will also be information on those releases. e.g. This includes a link to the pushlog containing changesets landed between two releases.

Listing of Known Releases

The firefoxreleases web command renders known Firefox releases from changesets in a repo. e.g.

A JSON view is available by using the json-firefoxreleases web command. e.g.

Filtering by platform is available by specifying the platform query string argument. e.g.


If you want to read this data from machines, a better source might be

Development Info

Please file bugs and feature requests against the Bugzilla component.

For real time support, make noise in #vcs on