Firefox Beta is the build for those who like a little bit of jeopardy, but who don’t want to risk everything by trying out Firefox Aurora, the early alpha build of Firefox. Firefox Beta gives you a sneak peek at the next version of Firefox six weeks ahead of its final release, offering a relatively stable build that’s not quite ready for primetime, but still pretty solid.

Whereas Firefox Aurora installs as a completely separate application alongside your existing Firefox installation, Firebox Beta will replace the stable build. Should you subsequently wish to go back to the safer version, you’ll need to manually download the stable version and install it over the top of the beta build.

Confirm which build you have by selecting About Firefox from the Firefox menu or button (it’s inside the Help menu if using the Firefox button).

Firefox 40 is now in the Beta channel. New features include:

- NEW. Support for Windows 10 including tablet mode
NEW. Download protection from potentially unwanted software
NEW. Suggested Tiles show sites that may be of interest, based on categories from your recent browsing history
NEW. Add URLs to a Hello conversation for additional context
NEW. New style for add-on manager based on the in-content preferences style
NEW. Improved scrolling, graphics, and video playback performance with off main thread compositing (GNU/Linux)
NEW. Smoother and more reliable CSS animations via asynchronous animations


Version 39 offers support for malware detection lookups and more