Mozilla Firefox 4 review

The long-awaited Firefox 4 is finally here, but is Mozilla's latest browser a must-have or a has-been? Read our review to find out.

Firefox 4 can even use your computer's graphics chip to speed up the rendering of animations and other graphically demanding page elements, although the company has yet to confirm which graphics chips are officially supported.

On a laptop with an Intel GMA 4500M HD integrated graphics chip, Firefox 4 managed a fast 35fps in Microsoft's fish tank animation test with 50 fish onscreen. Chrome 10 was slower, but still smooth, at 25fps while Internet Explorer 9 lagged behind at a sluggish 13fps. The GMA 4500M HD is a widely used chip, so Mozilla's rivals still have some work to do, but it's still early days for hardware accelerated browsing.

A modest but useful improvement is the refined interface for finding, installing and managing the multitude of add-ons available. It uses a larger window that makes better use of the available screen space. Many add-ons will need to be updated by their developers before they'll work with Firefox 4, but the browser automatically disables incompatible ones anyway.

Users of multiple computers may appreciate Firefox Sync which lets you sychronise your bookmarks, history, open tabs and other settings between multiple computers running Firefox 4. It's not a new feature, having previously been available as an optional add-on for previous versions. An intriguing option is the ability to run your own Firefox Sync server if you'd rather not have sensitive business data and settings passing through Mozilla's servers for compliance or commercial reasons.

Privacy-conscious users will be attracted to Firefox's ability to stop websites and advertising networks from tracking them as they browse from site-to-site. However, this feature relies on websites and advertising networks respecting the user's wishes unethical websites and ad providers could still track the user. If you still want to enable this feature, it's tucked away in an obscure corner of the Options dialog box.

So what's our verdict?


Firefox 4 is the best version of Mozilla's web browser yet. We're fond of the fast rendering speeds, the useful Tab Groups feature and the interface as a whole, even if it is a little derivative. We also like the broad selection of available add-ons. Although you can't go too far wrong with any of the modern browsers, Firefox 4 is our preferred pick.

Processor: Intel Pentium 4 or newer processor that supports SSE2 Memory: 512MB Graphics: not stated Hard disk: 200MB free hard disk space OS: Windows 2000 or later

Featured Resources

Security analytics for your multi-cloud deployments

IBM Security QRadar SIEM solution brief

Download now

Five reasons to move to the cloud

Join the enterprises moving their workloads to the cloud

Download now

Architecting hybrid IT and edge for digital advantage

Why business leaders should consider a hybrid IT strategy

Download now

Six reasons to accelerate remote asset monitoring with AI

How to optimise resources, increase productivity, and grow profit margins with AI

Download now

Most Popular

How to build a CMS with React and Google Sheets
content management system (CMS)

How to build a CMS with React and Google Sheets

24 Feb 2021
How to connect one, two or more monitors to your laptop

How to connect one, two or more monitors to your laptop

25 Feb 2021
Oxford University COVID lab falls victim to hackers

Oxford University COVID lab falls victim to hackers

26 Feb 2021