Thank you for your interest in using beta. Whether you are just curious or already using beta, this reference will help you have the best possible experience.

The Thunderbird Beta page contains details about whether you should use beta and other basic information – please read it first, then return to this article for more advanced information.

The Beta start page is a handy reference for frequently used links – available in Thunderbird as ALT > Go > Mail Start Page. The Beta release notes are also very informative.

How to help improve beta

• Join the beta community to ask questions and see current information about beta.
• Please test the both new and old features (for the next major release which will be Thunderbird 115 Supernova), and report bugs that you find.
• If you find a performance issue that reproduces in troubleshoot mode, create a performance profile and post it in a bug report.

Add-ons

Add-on authors are not obligated to have their add-ons work in beta. So expect some or all of your add-ons to not work. Or if they do work today, they may not work tomorrow. Consult the add-ons FAQ if you have difficulty.

Download locations

• Windows, Mac and generic linux
• Ubuntu from Canonical -- sudo snap install thunderbird --beta

How do I change from a beta version back to a release version?

How you change back to a release version depends on how you configured your profile data, and when you decide to make the change. If you only have one profile, then the best time to change is shortly before or within two to three weeks after a major version ships publicly, like when version 115 ships and the beta is still version 116. This timing will minimize the possibility that data structures have changed. You have two options:

1. Beta program installed in its own directory, beta data is in a dedicated profile, and you do not need any beta data (address books, local folders, pop folders, etc.) back in your production profile, and wish to remove the beta data and beta program from your system:
   • Start the release version of Thunderbird to use the profile manager.
   • Delete the beta profile using the profile manager, default name is “default-beta”.
   • Delete the beta version’s program directory in your OS.
2. Beta program installed in its own directory, beta data is in a dedicated profile, but you DO need beta data (address books, local folders, pop folders, etc.) copied back to your production profile. This gets messy and difficult, and is something you really want to avoid.
   • While running beta, export your address book(s) to file(s) as vCard, which you can then import into version 91 (but version 91's lower capabilities might mean the results will be less than perfect).
   • Open both of your profiles in your OS's file browser. One way of finding them is ≡ > Help > Troubleshooting Information > about:profiles.
   • Shutdown both versions of Thunderbird.
   • Backup your production profile.
   • Under the Mail directory you will find both Local Folders directory and pop account directories – you can copy the contents of these from the beta profile to your production profile, taking care to NOT overwrite any msgFilters.dat files (which contain your filter rules) in your production profile.
   • Imap accounts – there should be no need to copy any files from beta profile to your production profile.

Beta isn't for me. How can I help?

Get involved lists many ways for you to help in the community, and places to learn more about Thunderbird.