Microsoft Corp. said this week that its own speed tests prove Internet Explorer 8 (IE8) is faster than either Firefox or Chrome.
"These benchmarks necessarily characterize only a narrow set of the browser functions in a very constrained way," Microsoft's report said. "End users, however, do not operate in a controlled environment."
Microsoft's tests pitted IE8 Release Candidate 1 (RC1), which launched in late January, against Google Inc.'s Chrome 1.0 and Mozilla Corp.'s Firefox 3.0.5, a version from mid-December. The company timed how long it took each browser to completely render the 25 most-popular destinations on the Web, as ranked by the Web metrics firm comScore Inc., which included google.com, facebook.com, amazon.com, and others.
IE8 was fastest in rendering 12 of the 25 sites, said Microsoft, while Chrome took second by beating the others on nine sites. Firefox, meanwhile, was a distant third, coming in first on just four of the 25 domains.
Microsoft did not test other browsers, such as Apple Inc.'s Safari or Opera Software ASA's Opera, said James Pratt, a senior product manager on the IE development team, because it wanted to focus on rivals that "had a good share on the Windows platform."
Both Opera and Safari for Windows have shares of less than 1%, according to the most recent data from Net Applications Inc., with the former, on all platforms, accounting for 0.7% and the latter just 0.3%.