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Web Browser Grand Prix: Firefox 15, Safari 6, OS X Mountain Lion

Standards Conformance

Composite Scoring

The standards conformance composite is determined by dividing the results of each test by the maximum score of that test, then multiplying by 100 to get a percentage. The percentage results of the three tests are then averaged together to achieve a composite grade.

Chrome takes first place on both operating systems with a B-. It is followed by Safari in second place on OS X with Opera and Firefox caught up in a tie for last, both achieving an equal C. Opera manages an extra percentage point on Windows 7 to place second with Firefox close behind in third. Last place in Windows 7 goes to Microsoft's own IE9 with the only failing grade.

Drill Down

The charts below are for the three standards conformance tests: Ecmascript Language test262,, and The CSS3 Test.

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IE9 is significantly behind the curve in all three disciplines, while Chrome's better-than-average HTML5 and CSS3 scores allow Google to dominate standards conformance.