The result is the big three's best browsers yet: IE9, Chrome 10 and Firefox 4 RC. So which one deserves a place on your desktop?
IE9 vs Firefox 4 vs Chrome 10: appearance
The trio keep on-screen "chrome" to a minimum and don't look bad at all. From a purely aesthetic point of view IE9 looks nicest, but having everything on one line quickly gets cluttered.
Chrome is stripped back to the point of near invisibility, and Firefox 4 is the prettiest Firefox yet. Yes, that's a bit like saying "the smartest thing Charlie Sheen has ever said" but after years of blocky ugliness the new UI is a vast improvement, and this refined version is starting to grow on us. At least, it is on the PC. The default Mac interface doesn't quite work.
PRETTIER: Firefox's new UI is a dramatic improvement. It doesn't take up much room and it's a nice place to spend time
IE9 vs Firefox 4 vs Chrome 10: speed
Chrome 10 was the slowest on our test PC, running through the SunSpider benchmarks in an average of 346.0ms, with Firefox 4 achieving an average of 308.5. IE9 had the edge, though, with an average of just 288.8ms.
Let's try another one: version 6 of V8, Google's own benchmarking suite. You'd expect Google to do well here, and it did. Bigger numbers are better, and Chrome achieved 7,101 compared to 3,269 for Firefox and 2,053 for IE9.
So far so meh - "Google browser does well in Google benchmark" isn't a surprise - but it does demonstrate how the gaps between browsers are disappearing: in 2008, Chrome would routinely score ten times more than Firefox and IE wouldn't even feature.
One more? Let's give Mozilla's Kraken, the hugely demanding set of web-app tasks based on SunSpider, a go. Firefox powered through the enormous testing suite in 9,224ms and IE9 19,136ms. Firefox in "Mozilla has the best browser on Mozilla benchmarks" shocker? Nope: Chrome was narrowly ahead, coming in at 8,794ms.
It's clear that the browsers have been optimised for their preferred benchmarks, but what about real-world stuff? From hitting enter to finishing loading the TechRadar home page on a 20MBps DSL connection, Chrome took four seconds, Firefox five and IE nine (no pages were cached and we didn't have extensions, add-ons or other goodies installed or blocking content).
Fark.com took four seconds in Firefox, four in Chrome and six in IE. Online banking's login page took two seconds in Chrome, two in Firefox and three in IE.
Let's try something more challenging. Loading and starting to play Radiohead's Lotus Flower video on YouTube was three seconds in Firefox, three in IE and four in Chrome. Opening an existing file and having it ready to edit in Google Docs took four seconds in Firefox, four in Chrome and six in IE9.
There's clearly a pattern here. Firefox and Chrome are generally neck and neck in everyday performance, and IE9 lags narrowly behind. However, there really isn't much in it - and in most cases the ads are the bits that take the time, with pages' text, navigation elements and form fields appearing almost instantly.
IE9 vs Firefox 4 vs Chrome 10: stability and standards
The Acid 3 test is the, er, acid test for standards compliance, and if you'd told us a few years ago we'd be seeing IE get 95/100 we'd have burned you as a witch. But there it is in black and white (and yellow and...).
Firefox is narrowly ahead with 97/100, and Chrome is giving the teacher an apple and getting a gold star for its perfect 100/100 score.
There's more to standards than the Acid test, however. Different browsers support different bits of the HTML5 standards, so for example when it comes to video Chrome doesn't like H.264 - it prefers its own WebM video or Ogg Theora, which are the favourite formats of Firefox, too - whereas IE9 likes H.264 very, very much.
VIDEO SUPPORT: All three browsers are HTML5 friendly, but they support different video formats: Chrome and Firefox are playing WebM here while IE9 gets H.264
Video, of course, is a notorious browser crasher, so it's nice to have Chrome and IE9's ability to split individual tabs into different processes. This prevents a malfunctioning plug-in from wrecking the whole browser session, and makes it easy to kill misbehaving tabs.
Firefox has crash protection but it's still a one-process browser, so something going wrong in one tab could still affect everything else.
BACK AGAIN: IE9 can recover from crashes and unexpected shutdowns just like Firefox, although we wish the notification was more prominent
IE9 vs Firefox 4 vs Chrome 10: features
Firefox has the edge here: its pinnable App Tabs tuck away opened tabs such as email and web apps, while Tab Groups make it easy to organise large collections of open pages.
Firefox 4 also boasts some excellent synchronisation features. It doesn't just sync your bookmarks across devices; it takes your history and even your currently open tabs. If you're constantly moving from machine to machine you'll love this feature. Chrome has synchronisation too, but it doesn't extend to open tabs.
IN SYNC: Firefox and Chrome both have excellent browser synchronisation systems. To do it in IE9 you need a third-party extension
IE9 doesn't have syncing at all, but it does enable you to pin sites to the Windows 7 taskbar as if they were applications and drag a tab out to Snap it for viewing side by side with another. You also get a proper download manager, which Firefox has had since about 1957.
There's also a Chrome-style new tab page and Chrome-style searching in the address bar. Firefox retains the two-box approach, with the Awesome Bar for URLs and history and a separate search box - although confusingly, the Awesome Bar does search too.
EXTEND IE: It doesn't have the sheer range of Firefox's add-ons, but IE has enough available extensions to cover the essentials
Firefox is the most expandable here but Chrome is catching up fast, its Chrome Extensions and web apps becoming increasingly impressive. All three browsers' add-on galleries cover the basics - ad blocking, Flash blocking, Twitter clients and so on - but Internet Explorer's is the most limited. Firefox and Chrome are also skinnable, enabling you to change their default appearance.
IE9 vs Firefox 4 vs Chrome 10: verdict
You can prove pretty much anything with benchmarks, and while Internet Explorer did best in SunSpider it felt the slowest in real-word use. It's a really nice browser, though, and if you're the kind of user who doesn't really bother with extensions or fiddling around, you'll be perfectly happy with it. It does lag slightly behind its rivals in real world speed, but on a decent PC there's not much in it.
Firefox and Chrome were neck and neck in the performance stakes: on paper Chrome bests Mozilla's browser, but in practice the differences are insignificant. However, Chrome's ability to split tabs into individual processes should make it the more stable - although at the time of writing there seems to be a horrible bug in its handling of Flash.
KEEP APART: Tab Groups in Firefox make it easy to separate business and pleasure, or to keep different tasks separate
Do we have a winner? Firefox's Tab Groups and App Tabs are brilliant, and the browser's Swiss Army Knife reputation remains intact. If you use a lot of tabs and need lots of extensions then Firefox is the browser for you; if you're spending all day in a few web apps and your need for add-ons begins and ends with ad-blocking, then Google is your friend - or at least it will be once the Flash problem is fixed.
Liked this? Then check out Best browser 2011: which should you be using?
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