New Alpha Release: Tor Browser 13.5a9

by richard | June 11, 2024

Tor Browser 13.5a9 is now available from the Tor Browser download page and also from our distribution directory.

This version includes important security updates to Firefox.

End of Another Release Cycle

Tor Browser 13.5a9 is our (hopefully) final release candidate for Tor Browser 13.5. After this release, we will be focusing entirely on the major ESR-115 to ESR-128 transition over this summer, culminating in Tor Browser 14.0 in the autumn.

This has been a long release cycle, which means there is a lot of things we would ask users to test. In particular:

  • Bootstrapping on Android: We have both a new frontend and backend for tor daemon bootstrapping (the process of connecting to the Tor Network). We had hoped to port over the entire connect assist feature, but alas the release schedule did not allow for it. The new UX should have feature-parity with the Tor Browser 13.0. Work on connect assist on Android will contniue during the 14.0 release cycle over the summer.
  • Tor daemon configuration: As part of the Android bootstrapping work, we had to modify a lot of shared systems between Desktop and Android. All of the various environment variables and configuration options you are used to using in Tor Browser 13.0 should continue working as expected
  • Letterboxing Improvements: The desktop letterboxing UX (affectionately referreed internally as 'better-boxing') has seen an overhaul during this release cycle. It should now appear intentional, rather than a rendering bug. We have also addeed a few customisation knobs in about:preferences to modify the look and feel, without affecting your browser fingerprint.
  • Localisation Migration: We have been iteratively migrating/upgrading our localisation pipeline for various components in the browser. If we did everything right, then what was localised in Tor Browser 13.0 should remaing localised in Tor Browser 13.5.
  • Style Updates: The styling of onion-service network errors and of about:torconnect on Desktop has been updated and should fit in better with Firefox's own styling.
  • OS Deprecation Notification: Users of Windows 8.1 and lower and of macOS 10.14 and lower should get a notification in the message bar on startup notifing users that they need to upgrade their operating system to continue to receive updates long-term. Mozilla dropped support for these legacy platforms in Firefox 116, and so we must follow suit after the ESR-128 transition. Tor Browser 14.0 will not be supported and likely will not work properly on these older platforms.

Send us your feedback

If you find a bug or have a suggestion for how we could improve this release, please let us know. If you would like to contribute, our contributor guide can be found here.

Full changelog

The full changelog since Tor Browser 13.5a8 is:

This is a companion discussion topic for the original entry at