The Tor Project has announced the release of Tor Browser 15.0, now available for download, marking the first stable release based on Firefox ESR 140 and bringing an entire year’s worth of upstream improvements, privacy refinements, and security patches.
On desktop, the new version inherits a range of usability improvements from Firefox. The most visible change is vertical tabs, which stack open and pinned tabs along a sidebar, freeing horizontal space and improving navigation.
For those juggling multiple tasks, tab groups are another welcome addition. They let users organize open tabs into collapsible, color-coded groups, keeping browsing sessions tidy while maintaining Tor’s privacy-first behavior—since all tabs remain private and clear automatically when the browser is closed.
The address bar has also received Firefox’s latest enhancements, featuring a unified search button that allows on-the-fly engine switching and quick access to bookmarks, tabs, and actions from a single menu.
Moreover, Tor Browser 15.0 introduces a major change to how WebAssembly (Wasm) is managed. Previously disabled globally at higher security levels, Wasm control now falls under NoScript, the bundled security extension that already governs JavaScript behavior.
This move allows necessary components, such as Firefox’s PDF reader—now partially implemented in Wasm—to function safely while keeping the technology blocked on websites when using Safer or Safest modes. Users who had manually disabled Wasm in about:config are encouraged to revert to default settings to avoid unique browser fingerprints and maintain consistent privacy profiles.
On Android, Tor Browser 15.0 introduces screen lock, an optional privacy feature that secures your open tabs whenever you switch away from the app.
Once enabled under Settings > Tabs, your session locks automatically and requires fingerprint, face, or passcode authentication to reopen. While sessions are still cleared upon exit, this feature adds peace of mind when someone temporarily accesses your unlocked device — protecting your activity even when the app remains open in the background.
Keep in mind that Tor Browser 15.0 will be the last major release to support older Android versions (5.0–7.0) and x86 architectures on Android and Linux.
Starting with version 16.0, Mozilla’s Firefox base will drop these platforms to focus on modern systems and improved security. Tor developers confirmed they will continue to provide minor updates and security fixes for affected users until the next major release.
For more information about all the changes, see the official announcement.
