The viewport metatag was Apple's solution to the problem. It was adopted quickly by other platforms, but it was never put forward by the W3C. Microsoft brought this to light when they chose for IE10 to ignore the viewport metatag under certain circumstances. Instead, they opted to use CSS Device Adaptation , which is what the W3C are leaning on. In short, similar viewport properties are defined within CSS using the @viewport rule , instead of within the HTML. 1 2 3 4 @viewport{ zoom: 1.0 ; width : device-width; } Or, in accordance to our newer don't specify device width approach, we could set the following: 1 2 3 4 @viewport{ zoom: 1.0 ; width : extend-to-zoom; } Given that it's a work in progress, IE10 requires the prefixed version of the proposal, which looks something like this: ...