Mozilla Firefox 9: Faster on PCs, all-new on tablets

Tuesday, December 20th 2011. | Software News

Mozilla is laying claim to big performance improvements for Firefox 9, while Firefox for Android goes in for a shave and a haircut as it gets an entirely different look. Both desktop and Android updates are being released today.

mozilla firefox logoFirefox 9 (download for Windows | Mac | Linux |Android) continues the browser’s rapid-release development oscillation, where feature enhancements and performance improvements take the lead in alternating months.

The JavaScript improvement called Type Inference, which Mozilla spent more than a year developing, debuts on the PC version of Firefox. The short version is that sites that heavily rely on JavaScript–like Web apps or sites that render games, video, and 3D graphics–will render much, much faster.

What actually changed is this: A feature in Firefox’s SpiderMonkey JavaScript engine, Type Inference creates type information by both monitoring the types of values as the program runs and analyzing the program’s code. The type information then gets used during “just-in-time” compilation to generate more efficient code, and Mozilla says that major benchmarks like its own Kraken test and Google’s V8 show the browser running around 30 percent faster.

On Macs, OS X Lion users will finally see support for two-finger swipe gestures, which sounds more offensive than it is. This simply means that if you’ve got the latest Mac OS, it’ll be easier for you to jump from site to site. The Mac interface has also been tweaked to match the slight visual changes that arrived in Lion, and multiple monitor support in the browser has been improved.


Firefox 9 Android debuts a new way to interact with tabs, and ports the browser's signature bigger Back button to the mobile operating system. These screenshots are from the Aurora release of Firefox 9, so there might be slight changes in the stable version. (Credit: Mozilla)

Web developers get some attention in Firefox 9, too. The most important developer changes in Firefox 9 are that sites that run Ajax or download large data sets will load faster, and sites can now display content as it’s being downloaded thanks to new support to chunking XHR requests. While a technical term, the upshot of chunking XHR requests is that developers can build Web sites to receive large amounts of data faster, and thus making the site itself faster to load. JavaScript can also be used to detect a browser’s Do Not Track preference, the option that tells Web sites not to use cookies to track a person’s browsing behavior. A longer list of Web developer changes in Firefox 9 is available.

Firefox’s new Android tablet interface makes it to the stable version of the browser, and the interface changes are drastic. As I noted when the new look arrived in the Aurora channel in September, the Back button has moved to the location bar, which has been stretched to the right edge of the screen to put Refresh and Bookmark buttons closer at hand. Tabs have been moved to a hidden menu when in portrait mode, and appear much larger than they have before when they’re exposed. There have been some performance gains, too, as Mozilla says that people ought to see faster app load times.

This new look won’t be around long, though. Mozilla plans to rebuild its app using native Android code, and the mock-ups show even more changes to the interface. One change that does look like it’ll stick around is a new sidebar approach to the Awesome Bar, so that when you tap the location bar, tabs for Bookmarks, Open tabs, History, and Sync appear on the side while you scroll in the middle of the window.

There have also been two big improvements to HTML5 support in Firefox for Android. The browser now supports the Input Tag for cameras, which means that developers can build mobile sites and apps that will take pictures and scan bar codes without leaving Firefox. Mozilla created a demo of the Input Tag here.

The second change supports the HTML5 Form Validation API, for automatic form-field validation. Basically, it will be easier to get the browser to validate typed text.

While the future of Firefox for Android lies in abandoning the current interface for the predicted massive speed gains from native Android code, the PC version of Firefox looks to address ongoing add-on compatibility issues, and give the browser a more seamless automatic update experience.

Related For Mozilla Firefox 9: Faster on PCs, all-new on tablets