Tor Browser 9.0a1 is now available from the Tor Browser Alpha download page and also from our distribution directory.

Note: this is an alpha release, an experimental version for users who want to help us test new features. For everyone else, we recommend downloading the latest stable release instead.

This release features important security updates to Firefox.

Tor Browser 9.0a1 is the first release in the 9.0 alpha series. It contains all the improvements and fixes from the 8.5 release as well as other new features:

Tor Launcher is getting tighter integrated into the browser as a preparation step for the switch to Firefox 68 ESR. That results in it not showing up anymore on the about:addons page while still being available (and we don't need to make a code-signing exception for it either anymore, which is nice). See the underlying proposal for this decision for full details.

We backported Mozilla's Letterboxing feature which allows us to finally tackle the problem of not properly rounded screen dimensions in case users start to maximize or otherwise resize the browser window. Letterboxing is off by default for now, although we plan to enabled it in one of the upcoming alpha releases. If you want to check it out and report issues please add the privacy . resistFingerprinting . letterboxing preference on about:config and set it to true . Many thanks to Tom Ritter and anyone else at Mozilla who has been working on that problem and designing the current approach.

The full changelog since Tor Browser 8.5a12 is: