Mozilla Firefox 4 review

Having topped Internet Explorer to become Europe’s most used browser, Firefox now oddly finds itself under greater pressure than ever. Not only has Microsoft largely got its act together with the much-improved Internet Explorer 9, Mozilla’s once-close ally Google is also gobbling up market share with Chrome. Can the long-awaited launch of Firefox 4 prevent Mozilla being squeezed out by the two browser superpowers?

Interface

All the major browsers are currently going through a minimalist phase, and Firefox 4 is no exception. The dated-looking dropdown menus of Firefox 3.6 have been shoehorned into a single Firefox button in the top-left of the browser, although there remains the option to turn on the old-school menu bar for traditionalists.

Gone, too, are the rest of the browser buttons, with only back, forward and the stop/reload button remaining permanently in place. The result is a clean, modern-looking browser with tabs now nestling neatly at the top of the window.

If all that sounds a tad too austere, Firefox provides the option to customise the toolbars, so you can reintroduce Print and History – or add a button for one the most interesting new features in Firefox 4: Tab Groups.

Designed for power browsers with multiple tabs open simultaneously, Tab Groups (confusingly also called Panorama in some places) allow you to drag and drop open pages into different categories: one group for news sites and another for webmail accounts, for example, each contained within distinct browser windows.

Tab Groups can be renamed and resized, with the grid of thumbnails shrinking into a neat stack if the group’s window isn’t big enough to accommodate them all. Better still, you can have your customised groups ready and waiting for you the next time you fire up the browser by choosing “Show my windows and tabs from last time” from Firefox’s General Options menu. It’s a magnificent feature, although the Aero glass-style interface can hinder performance on slower PCs.

Features

Aside from Group Tabs, Firefox is relatively light on new features. The most notable newcomer is Sync, which has been promoted from an add-on to a core browser feature. This not only synchronises your bookmarks, passwords and browsing history across your different PCs, but it also open tabs, allowing you to dash out of the office and pick up surfing where you left off at home. Sync also works with the Firefox Home iPhone app and the forthcoming Android version of the browser, providing near-seamless integration between mobile and desktop browsing.

The other big new feature is alleged protection from advertisers who track you from one website to another. Here, Mozilla has taken a markedly different approach to Microsoft, which introduced a similar feature in Internet Explorer 9. Instead of providing a blacklist of ad-tracking services, Firefox 4 transmits a “Do Not Track HTTP” header to websites.