Detect IE in JS using conditional comments

// ----------------------------------------------------------
// A short snippet for detecting versions of IE in JavaScript
// without resorting to user-agent sniffing
// ----------------------------------------------------------
// If you're not in IE (or IE version is less than 5) then:
//     ie === undefined
// If you're in IE (>=5) then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}
// And to detect the version:
//     ie === 6 // IE6
//     ie > 7 // IE8, IE9 ...
//     ie < 9 // Anything less than IE9
// ----------------------------------------------------------
 
// UPDATE: Now using Live NodeList idea from @jdalton
 
var ie = (function(){
 
    var undef,
        v = 3,
        div = document.createElement('div'),
        all = div.getElementsByTagName('i');
 
    while (
        div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
        all[0]
    );
 
    return v > 4 ? v : undef;
 
}());

So far there's been 13 Responses to
“Detect IE in JS using conditional comments”

1. criography August 21st, 2010 at 9:44 am

   Ooh, that’s really clever! Thanks James!

2. urssur August 29th, 2010 at 1:37 pm

   that is cool , using what ie cant do in order to see if it is ie, that is crazy good.

   I just got some ideas of how to use this in a webapp.

   Thanks dude

3. Waterontharder October 5th, 2010 at 9:46 am

   Nice tips! That’s really clever! Thanks James! Keep on the good job!

4. prochor666 December 8th, 2010 at 7:36 pm

   W000000000W :). Realy nice.

5. erd January 21st, 2011 at 10:03 pm

   Thanks its always good to be able to see who is still using the very bad ie browser.

6. Nyuszika7H January 30th, 2011 at 5:30 pm

   There’s a much easier way to do that.

   var IE; //@cc_on IE = navigator.appVersion;

   Usage: if (IE) {...}, if (IE <= 6) {...}, if (IE < 9) {...}, if (IE == 7) {...} etc.

   //@cc_on is a conditional comment, just like <!--[if IE]>. Since it’s a comment, other browsers will just ingore it.

7. Vince February 1st, 2011 at 3:30 am

   Sure it’s cleaver, but how is this any different from testing navigator.appName and all the other navigator.* properties ?

   You’ve still got to put IE specific code in regardless.

8. Nyuszika7H February 15th, 2011 at 1:08 pm

   James’ solution is 191 bytes minified, but mine is only 40.

9. Aldo_MX February 17th, 2011 at 8:52 pm

   @Nyuszika7H: I think you meant

   var IE; //@cc_on IE = parseFloat(navigator.appVersion);

   So is not 40 bytes anymore 😛

   Anyway, a more accurate IE detection:

   <script> var IE_Version; var IE_Engine; /*@cc_on @if( @_jscript_version < 9 ) { if( @_jscript_version >= 5.8 ) IE_Version = 8; else if( @_jscript_version >= 5.7 ) { if( window.XMLHttpRequest ) IE_Version = 7; else IE_Version = 6; } else if( @_jscript_version >= 5.6 ) IE_Version = 6; else if( @_jscript_version >= 5.5 ) IE_Version = 5.5; else if( @_jscript_version >= 5.1 ) IE_Version = 5; else if( @_jscript_version >= 3 ) IE_Version = 4; else IE_Version = 3; } @else { IE_Version = @_jscript_version; } @end @*/ if(IE_Version) { IE_Engine = parseFloat(navigator.appVersion); } </script>

   This way you when IE_Version != IE_Engine the user is either using compatibility mode or cloaking

10. James February 18th, 2011 at 3:42 am

    @Nyuszika7H, @Aldo, you’re both missing the point. My solution doesn’t rely on feature detection/inference or sniffing the UA string. Both these things are considered bad-practice by some and so I wanted to offer a potential solution. There are smaller solutions available if you are not concerned about the arguments against.

11. LEDs Lights March 10th, 2011 at 7:54 am

    Hey James, That was useful clear, and helpful info as usual from Webapp. Thanks and keep on the good works. ..

12. OC Wedding Photographer March 30th, 2011 at 3:15 pm

    I like the code … It’s clean and short … Great work James

13. Clive Walkden June 17th, 2011 at 9:18 am

    Like it a lot, nice and clean. Thanks for posting this. Nice to see new ways of detecting the bane of our lives!