Firefox 4 adds speed and tames your tabs

The need for speed

Web pages are becoming ever larger and slower to load, and Web-based apps are proliferating -- so browser speed is more important than ever. In tests, I found that Firefox 4 didn't rate as fast as the current versions of Internet Explorer, Opera or Chrome on the SunSpider JavaScript Benchmark, although it rated significantly faster than Safari.

In my tests, I used a Dell Dimension 9200 with a 2.4-GHz Intel Core 2 Quad processor and 2GB of RAM, running Windows Vista. I ran three sets of tests on each browser and averaged the results.

Firefox 4 clocked in at an average speed of 319.4 milliseconds (ms) to complete the tests, versus the fastest, Internet Explorer 9, at 277.3ms. Opera 11.01 came in at 308.7ms, Chrome 10.0.648 at 312.1ms and Safari at 417.1ms. That said, it's unlikely that you'll notice a speed difference among Firefox 4, Internet Explorer, Chrome and Opera -- a few milliseconds difference here or there won't likely be apparent.

Firefox, like IE9, uses your computer's GPU to accelerate processing-intensive work such as for playing games and displaying 3D graphics. Mozilla and Microsoft have been trading barbs over which browser is superior in this respect, but there are currently no standard tests for measuring this.

HTML5 support

Firefox 4 does an excellent job of supporting Web standards, including the upcoming HTML5 standards. On the HTML5 test page, which tests overall support of HTML5, it scored 240 out of a possible 400, second only to Chrome 10's score of 288. Opera came in just behind Firefox at 234, followed by Safari with 228 and IE9 at 130.

Firefox did well but not perfectly on the Acid 3 Test, which rates the degree to which a browser follows a number of Web standards, especially JavaScript and the Document Object Model (DOM). It scored 97 out of 100 and rendered the test page perfectly except for showing a box as gray when it should have been blue. Opera, Safari and Chrome all scored 100 and rendered the page perfectly. IE9 scored a 95 and made the same error rendering the page as Firefox 4 did.

Firefox 4 also did an excellent job of playing HTML5 video on every page that I visited, except for a website that Microsoft set up for demonstrating HTML5 -- the videos there either didn't display properly or didn't work at all. Otherwise, Firefox displayed every page I visited without any errors.

Other features

Firefox first gained popularity (at least in some part) because of its many add-ons. In this version, the Firefox Add-Ons Manager has been given a moderately useful facelift. The manager now opens into a full window in its own tab, rather than into a small pop-up window, which makes it easier to navigate.

In addition, when you click the More link next to any add-on, you'll get much more information about it than previously, including the date the add-on was installed or updated, a link to its home page and a full description.

However, when you install or uninstall add-ons, you'll still have to restart Firefox -- unlike Chrome, in which no restart is required.

Firefox 4 also introduces a do-not-track feature, which lets you tell websites you visit that you don't want your behavior tracked. To turn it on, click the Firefox button and choose Options (on a Mac, go to your Firefox Preferences), click on the Advanced tab, then click the General subtab and check the box next to "Tell web sites I do not want to be tracked." In addition, Mozilla has also made an array of other behind-the-scenes tweaks to improve security.

Turning this on does not guarantee that websites will not track you, because there's no requirement that sites adhere to it. Still, some should respect it, so it's a useful feature.

Speeding up the revision cycle

Firefox 4 is a big improvement over Version 3, but it took Mozilla far too long to get there. Firefox 3.5 was released in June 2009, which means that it has taken nearly two years to produce a major upgrade. That's as glacial a revision cycle as Microsoft's -- the company took two years to upgrade Internet Explorer from Version 8 (released in March 2009) to Version 9 (March 2011).

It's an eternity in browser time. Mozilla has recognized that, and says that it will dramatically speed up its revision cycles. If it doesn't, it may well be leapfrogged by Chrome, which has a much more aggressive revision cycle.

The bottom line

With Firefox 4, the browser has gotten a significant overhaul, offering improved speed and a cleaner interface that gives more screen real estate to Web content. Most useful are Panorama's superb tab-handling features and the cross-platform, multidevice synchronization power of Sync.

For those who frequently keep many tabs open and want a way to tame them, it's clearly the best browser out there. But even ignoring Panorama's capabilities, Firefox users and those who may have stayed away because of Firefox's cluttered interface will want to give it a try because of its increased speed and clean interface -- and because Firefox still has the largest collection of add-ons of any browser.

Preston Gralla is a contributing editor for Computerworld.com and the author of more than 35 books, including How the Internet Works (Que, 2006).