Firefox 4 beta 1 is a smart-looking, snappy performer

Speedier performance

Betas are often notorious for laggard performance, but even in this first beta, Firefox 4 is faster than version 3.6, the current release. Web pages seem to load far more quickly, and tests bear that out. SunSpider JavaScript benchmark tests on my Windows Vista PC show that Firefox 4 is nearly 30% faster than version 3.6, but still lags significantly behind Opera 10.6, Chrome 5, and Safari 5.

I tested all five browsers, as well as Internet Explorer 8, running the test three times on each, and found that Opera finished in an average of 342 ms, Chrome in 361, Safari in 377, Firefox 4 in 651, Firefox 3.6 in 901, and Internet Explorer 8 in 5,035. (Computerworld reporter Gregg Keizer ran separate SunSpider tests and got similar results overall, although in his tests Safari edged out Opera for the lead.)

It's a big improvement over the existing version of Firefox, and subsequent betas may get faster. But it's unlikely that this version of Firefox will be improved so much that it rivals Opera, Chrome or Safari for speed.

Changes under the hood and what's next

In addition to what you see, Mozilla says that it's also made a number of changes under the hood, such as better crash protection. When a tab running an Adobe Flash, Apple QuickTime or Microsoft Silverlight plug-in freezes or crashes, your other tabs will still work -- and the crashed tab can be reloaded to see if it will work this time around.

Mozilla also claims improvements in its handling of CSS that will make pages load faster and allow designers to build better-looking pages. It also touts its implementation of the WebSockets API, a tool for bi-directional, full-duplex communications between the browser and the server, to allow developers to better build real-time Web applications such as for gaming.

Mozilla also says that upcoming versions of Firefox 4 will allow settings, passwords, bookmarks, history and open tabs to be synchronized across multiple devices, including smartphones. There is an add-on from Mozilla called Firefox Sync that does this, but I was unable to get it to work properly with Firefox 4. Mozilla also promises that Firefox will be even faster, and that there will be new privacy controls.

The bottom line

This first beta of Firefox 4 is impressive, modernizing what was becoming a very dated-looking browser. The new interface tweaks make the browser sleeker and simpler to use. It's also good to see Firefox speed up, although it still lags behind Opera, Chrome and Safari.

But the browsing experience is about much more than speed. Let's not forget Firefox's vast library of useful extensions and other add-ons, which none of its competitors come close to. While many of these add-ons don't work with the current beta, most of them will by the time Firefox 4 ships, and that gives Firefox a huge advantage over other browsers.

I have used this beta without a glitch, although the usual caveats hold about not using beta software on a production machine. However, this beta is stable enough that if my favorite add-ons worked with this version of Firefox, I'd use it as my main browser today.

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