Mozilla has released the latest version of its popular web browser – Firefox 4 Beta 11.

Since the launch of version 4 Beta 10 two weeks ago, the browser has seen some considerable stability and performance improvements. As well as this, the new version has a new “Do Not Track” feature, which aims to enhance user privacy.

The “Do Not Track” feature was resurrected by the FTC (Federal Trade Commission) in 2010 in an effort to increase the privacy of internet users.

The feature essentially lets users opt-out of behaviour tracking by advertisers through cookies and other browser-based methods. For example, if a user selects ‘Do Not Track’, it will block their shopping activity and subsequently stop advertisers from serving customised ads based on their past shopping behaviour.

This opt-out solution is great for consumers who’d rather not have the commercial version of Big Brother watching their every online move. However, it’s not so great for online marketers who rely on user data for their ad targeting.


A recent Mozilla blog post explained the new feature;

“With the integration of the “Do Not Track” option into Firefox 4 Beta, you can now check a “Do Not Track” box in the “Advanced” screen of Firefox’s Options. When this option is selected, a header will be sent signaling to websites that you wish to opt-out of online behavioral tracking.  You will not notice any difference in your browsing experience until sites and advertisers start responding to the header.”

For a good technical summary of “Do Not Track”, visit the blog of Mike Hanson – Principal Mozilla engineer –

The development of Firefox 4 is approaching the finishing line. Firefox 4 Beta 10 was release two weeks ago, and it shouldn’t be long before the full release makes its debut.

If you can’t wait until that time, Firefox 4 Beta 11 is now available to download and test at