A look behind the scenes of how Microsoft tests Internet Explorer 9

By Tom Warren, on 17th Nov 10 8:23 pm with Comments Off

Microsoft released a seventh and likely final Platform Preview build of Internet Explorer 9 today  and touted a big jump in JavaScript performance. How exactly does Microsoft test its next generation browser though?

Mike Decker, senior test lead of the IE team

In a video entitled “Behind the browser”, Microsoft’s Mike Decker, senior test lead of the Internet Explorer team, reveals that Microsoft measures the performance of IE “hundreds of times” a day. The software maker uses thousands of tests which result in “anywhere from 5 to 6 million+ different metrics that we end up analyzing,” according to Decker. Windows users spend half their time inside a web browser according to Microsoft so it’s important that the IE test team gets performance spot on.

Beyond analyzing data metrics and benchmarks Decker also reveals that Microsoft had to build its “own version of the Internet” to measure the performance of the browser.  Microsoft’s test labs replicate different network topologies and server configurations as well as different client configurations. The software giant measures everything from memory usage to CPU utilization to get a represntative sample of what customers see in their real world experience. The tests are run against hundreds of machines ranging from low-end netbooks to high-end 8-core desktops. Microsoft’s goal is to ensure IE9 is a “great experience” across all ranges of PCs.

Microsoft's IE tests running on netbooks

Microsoft’s work hasn’t gone unnoticed. Early W3C standards tests revealed that Microsoft scored 100% in a number of features. Although the tests were early, they indicate how far Microsoft has come with its latest browser. Microsoft has targeted developers in a heavy way with Internet Explorer 9. IE 9 takes advantage of the power of the GPU for all page rendering and developers can exploit this using CSS, DHTML and javascript. A new JS engine (codenamed Chakra) is also built into Internet Explorer 9 with greater interoperability and standards support all round. Features such as rounded corner CSS support are now built in.

Microsoft has also introduced broader support for HTML5 in IE9 through its new script engine. Microsoft recently performed W3C Web Standards tests on IE9, including HTML5, SVG 1.1 2nd edition, CSS3 media queries, CSS3 borders & backgrounds, CSS3 selectors, DOM level 3 core, DOM level 3 events and DOM level 2 style. Microsoft’s IE9 is the first and only browser to deliver full hardware acceleration of all HTML5 content. Other competitors, including Mozilla and Google, are planning select hardware acceleration but at the moment Internet Explorer 9 wins hands down.

Microsoft’s IE9 usage increased rapidly in the month of October. Internet Explorer 9 usage on Windows 7 has increased with 1.46% of Windows 7 users now using IE9 as their daily browser. This is an increase of around 2.5 times, up from 0.61% in September. Microsoft recently revealed that the Internet Explorer 9 beta had been downloaded over 10 million times making it the most downloaded beta release of Internet Explorer ever. Microsoft’s test drive site has had over 37 million page views and 13,000 pieces of developer feedback submitted.

Microsoft’s latest Platform Preview build, version seven, includes 354% better JavaScript performance according to WebKit SunSpider benchmarks. This is likely Microsoft’s final Platform Preview developer build until the Release Candidate. Microsoft previously revealed that there will be no beta 2 of Internet Explorer 9. Dean Hachamovitch, VP of Microsoft’s IE team, revealed the IE9 platform is “nearly complete” in late October.