Thunderbird Beta

Beta is a testing and development platform. Users of beta versions can assist by testing fixes and feature changes before they are made available in regular releases, and by giving feedback. But the platform should be considered to be unstable. Note also, add-ons may not work or unexpectedly break. If you require add-ons you should consider using the normal release, rather than beta.


Betas serve multiple purposes:

  • From a user point of view, using a beta and providing feedback is a a great and easy opportunity to be involved in process of improving their favorite open-source software - an opportunity which requires little or no techincal skill. And because beta gets fixes before release, a user can get relief from a problem that has been fixed but is not yet available in a normal release.
  • From a developer and release management point of view, beta is a secondary test bed for patches and features which have already been used in daily build channel. Overall stablility and quality is monitored, so that regressions are found and fixes verified before the code moves to a release version.
  • Add-ons authors use the beta channel to develop, update, and fix their add-ons.

While beta is considered to be unstable, it is an explicit goal that quality and stability be sufficiently high for the platform to be usable by adventurous users on a continuous, daily basis. And you giving feedback helps make that possible.

Installion and updates

You can get the beta from the channel page. When you run the beta, updates are pulled from the "beta channel" so that you get beta updates, not normal release updates. Updates occur rougly every 6 weeks, and on an as needed basis determined by developers and Thunderbird release management.

You can also run the normal release of Thunderbird "at the same time" by installing the beta into a different directory than the release version. (And when the normal release is running, its updates come from the "release channel", not the beta channel.)

Give Feedback

User feedback and user investigations are essential to the improvement of Thunderbird. You are encouraged to file support requests and issues in appropriate venues:

To see what others are saying about beta, see:


Add-ons other than Lightning (the calendar application) frequently may not work in the beta environment, especially after beta version 60. If you require many add-ons you should consider using the normal release.

That said, if you still wish to use beta but are having issues with add-ons please:


A channel is a mechanism for managaing the update process. A download is set for a specific channel, and that installation receives updates only for that channel according to the configuration setting in the program directory. Thunderbird has three channels

  • Release - the most stable platform, with major new versions roughly every 10 months, and minor versions every 6 weeks
  • Beta - pre-release platform described above
  • Daily - is an highly unstable testing and development platform, the intial location where developer patches land for new features and fixes.
// These fine people helped write this article:Wayne Mery, Ryan Sipes. You can help too - find out how.

Was this article helpful? Please wait...

Volunteer for Mozilla Support