Detect Metro UI Version of IE

Question

What's the fastest method, to detect User-Agent as metro UI version of internet-explorer >=10 ?

Answer 1

So, there doesn't appear to be a definitive test to identify Metro IE vs Desktop IE, but there does seem to be a few different pieces of data you can attempt to use to assume that it is Metro. Unfortunately, none of the items I have found can't be explained away by other settings. In other words, for all the "feature" tests I have found, Desktop IE could be configured in a way to trick the tests into thinking it was running on Metro.

Is ActiveX disabled (Metro doesn't allow any activex content, but desktop IE can have it set to disabled as well):

function isActivexEnabled() {     var supported = null;             try {         supported = !!new ActiveXObject("htmlfile");     } catch (e) {         supported = false;     }      return supported; } 

User Agent string check (Metro will always run in 64bit mode, but won't on a 32bit machine, and Desktop IE can be configured to run in 64bit mode as well not sure how popular either of those options will be)

function isWin64() {     return navigator.platform == "Win64"; } 

Full screen check (Metro will always be in full screen mode, however Desktop IE can also run in full screen mode, but this could be used as supporting evidence of Metro mode)

function isFullScreen() {    return (window.innerWidth == screen.width &&             window.innerHeight == screen.height); } 

In short, I think you have to try to check a bunch of features, and then guess, there is no definitive way. Or you could just accept that MS doesn't want you to do this, and use feature detection for the features you want to use.

For those that want to try to provide UI to refer to the containing browser UI (to indicate how to Pin the web page for example), keep in mind that other Metro apps can embed the IE10 Metro browser as a control, so even if you could identify the browser as Metro vs desktop, the UI might not be where you'd attempt to refer to it, so this can end up being a pretty tricky situation to get right 100% of the time. So either, don't try, or you could attempt the other detection techniques and accept that there are use cases that you could be displaying the wrong UI.

Answer 2

I don't believe there is a way to determine if a request is coming from the Metro version of IE10 versus the regular desktop mode version. Metro IE has no unique HTTP headers or user-agent string to identify it by.

Internet Explorer 10 User Agent Strings On Windows 8 64bit

Metro IE10 is a 64-bit application, so you'll see "Win64" in the user-agent string. Regular desktop IE10, by default, is 32-bit and will show "WOW64". You could sort-of make an educated guess based on this, but you would falsely identify anyone who chose to run the 64-bit version of IE10 in desktop mode. As you can see from that chart, the user-agent strings are identical. [edit: as noted in the comments, this won't work for 32-bit PCs.]

I could see why you may want to detect Metro IE, but this type of "browser sniffing" is generally discouraged because it's so cumbersome and error-prone. It would be best to feature test for certain browser functionality that you require using something like Modernizr, if you can.