The Tor Browser 13.0 update introduces several long-awaited improvements, including a landscape aspect ratio, a fix for the "red screen of death," and several enhancements from Mozilla's Firefox ESR 115. Updated app icons and GUI elements are also part of the mix, though Tor Browser retains its basic look and feel.
For many users, the new landscape aspect ratio is the biggest change in this release. Tor Browser previously limited its inner content window to 1000 x 1000 pixels, which isn't wide enough for some modern websites (and often triggers the mobile versions of webpages). Now, you can size up to 1400 x 900 pixels, which is much more appropriate.
Tor Browser is still enforcing its "buckets" system—there are only a handful of content window sizes to choose from, and if your container window exceeds the size of your content window, Tor Browser will use letterboxing to fill in the gaps on the sides of webpages. The "buckets" system makes it harder for websites to fingerprint Tor Browser users. Tor Project believes that 1400 x 900 will become the most popular bucket, so in theory, it should provide the maximum amount of anonymity.
Tor Browser 13.0 also fixes the dreaded "red screen of death" that's plagued users since the Tor Browser 10.5 release. This is all thanks to a new "about:tor" homepage that looks quite nice and ditches the legacy Tor network connectivity check. Non-default Tor Browser configurations lack the modern bootstrapping protocol and may still benefit from this connectivity check, but as Tor Project notes, none of the major Tor Browser offshoots use "about:tor" as their homepage.
Of course, this is the first Tor Browser release based on Firefox ESR 115, so it comes with plenty of small changes and enhancements. Firefox ESR 115 has some significant accessibility upgrades, such as improved screen reader support, keyboard navigation for in-website calendars and date pickers, plus proper UI and content scaling for Windows users with the "Make text bigger" accessibility setting enabled. You'll also notice improved performance on monitors with a refresh rate of 120Hz or greater, and touchpad gesture navigation (specifically two-finger forward and back) now works on Windows.f
Most of the other changes introduced in Tor Browser 13.0 are purely aesthetic. You'll see a fancier app icon on your desktop, many of the browser's UI elements have been gussied up, and the "about:tor" homepage uses a more minimal design with a shortcut to the onionized version of DuckDuckGo. Tor Browser hopes that these aesthetic changes will reduce user error and make the Tor Browser more inviting. This makeover was inspired by Tor Project's work on the Mullvad Browser—an offshoot of Tor Browser that doesn't use the Tor network.
The Tor Browser 13.0 release is available from the official download page and distribution directory. Do not install Tor Browser from third-party sources. Auditing information can be found on GitHub, and a full changelog is located at the bottom of Tor Project's most recent blog post.
Source: Tor Project