Faster, Safer, Smarter, Better

Things move quickly online, and we’ve beefed up the engine that runs Firefox to make sure you can keep up: Firefox 3.5 is more than twice as fast as Firefox 3, and ten times as fast as Firefox 2. As a result, Web applications like email, photo sites and your favorite social networks will feel snappier and more responsive.

More Ways to Keep You Safe
Keeping you safe while you surf is our top priority, which is why we’ve upgraded our anti-phishing and anti-malware technologies and have added private browsing and “forget this site” options to ensure your privacy. Plus, our open source security process means we have experts around the globe working around the clock to keep you (and your personal information) safe.

One Size Doesn’t Fit All
Everybody uses the Web differently, so why should your browser be exactly like the next guy’s? Whether you’re into chatting, cooking or coding, Firefox has more than 6,000 add-ons to help you customize it to fit your exact needs.

Advancing the Web
We’ve been working hard to make sure Firefox brings you the best of the modern web. With new features like private browsing, tear-off tabs and enhancements to the Awesome Bar, plus major performance enhancements, you’ll enjoy life on the cutting edge.

New In Firefox 4.0:
* Tabs are now on top by default on Windows only - OSX and Linux will be changing when the theme has been modified to support the change.
* On Windows Vista and Windows 7 the menu bar has been replaced with the Firefox button.
* You can search for and switch to already open tabs in the Smart Location Bar
* New Addons Manager and extension management API (UI will be changed before final release)
* Significant API improvements are available for JS-ctypes, a foreign function interface for extensions.
* The stop and reload buttons have been merged into a single button on Windows, Mac and Linux.
* The Bookmarks Toolbar has been replaced with a Bookmarks Button by default (you can switch it back if you'd like).
* Crash protection for Windows, Linux, and Mac when there is a crash in the Adobe Flash, Apple Quicktime or Microsoft Silverlight plugins.
* CSS Transitions are partially supported.
* Full WebGL support is included but disabled by default at this time.
* Core Animation rendering model for plugins on Mac OS X. Plugins which also support this rendering model can now draw faster and more efficiently.
* Native support for the HD HTML5 WebM video format.
* An experimental Direct2D rendering backend is available on Windows, turned off by default.
* Web developers can use Websockets for a low complexity, low latency, bidirectional communications API.
* Web developers can update the URL field without reloading the page using HTML History APIs.
* More responsive page rendering using lazy frame construction.
* Link history lookup is done asynchronously to provide better responsiveness during pageload.
* CSS :visited selectors have been changed to block websites from being able to check a user's browsing history.
* New HTML5 parser.
* Support for more HTML5 form controls.