IE11 detect whether compatibility view is ON via javascript

Question

does anyone know how to check if IE 11 compatibility mode is ON when I'm on a website through javascript?

I added the url to the list compatibility view settings. But when I do

navigator.userAgent

in developer tools, it returns

Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; .NET4.0E; .NET4.0C; .NET CLR 3.5.30729; .NET CLR 2.0.50727; .NET CLR 3.0.30729; InfoPath.3; rv:11.0) like Gecko

Looking at the microsoft website (http://msdn.microsoft.com/en-us/library/ie/hh869301(v=vs.85).aspx), it says

The compatible ("compatible") and browser ("MSIE") tokens have been removed.

Any help on detecting whether a page is using compatibility view via javascript would be really helpful. Thanks in advance.

Have you looked into document.compatMode and documentMode? (I don’t now if those are relevant/available in IE 11 any more.) — CBroe
May I ask why you want to know if the user is in compat mode? — Sampson
I just doing some testing. In previous IE versions, there would be a "broken page" icon in the url bar. but in IE 11, there's no way to tell whether if the page is using compat view on or not. — slee

jaegs jaegs · Accepted Answer · 2016-01-21T16:19:30

SOLVED

While searching for an answer to this question myself, I found this solution from Nenad Bulatovic in another thread but his response wasn't marked as the correct answer. I tested this out in IE11 and downgrading to IE5 and found that it works for IE7-IE11, which is great. I wanted to share it here in case anyone else finds it useful.

iecheck.js

function trueOrFalse() {
    return true;
}

function IeVersion() {
    //Set defaults
    var value = {
        IsIE: false,
        TrueVersion: 0,
        ActingVersion: 0,
        CompatibilityMode: false
    };

    //Try to find the Trident version number
    var trident = navigator.userAgent.match(/Trident\/(\d+)/);
    if (trident) {
        value.IsIE = true;
        //Convert from the Trident version number to the IE version number
        value.TrueVersion = parseInt(trident[1], 10) + 4;
    }

    //Try to find the MSIE number
    var msie = navigator.userAgent.match(/MSIE (\d+)/);
    if (msie) {
        value.IsIE = true;
        //Find the IE version number from the user agent string
        value.ActingVersion = parseInt(msie[1]);
    } else {
        //Must be IE 11 in "edge" mode
        value.ActingVersion = value.TrueVersion;
    }

    //If we have both a Trident and MSIE version number, see if they're different
    if (value.IsIE && value.TrueVersion > 0 && value.ActingVersion > 0) {
        //In compatibility mode if the trident number doesn't match up with the MSIE number
        value.CompatibilityMode = value.TrueVersion != value.ActingVersion;
    }
    return value;
}

iecheck.html

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Testing IE Compatibility Mode</title>
    <script src="iecheck.js" type="text/javascript"></script>
</head>
<body>
<div id="results">Results: </div>
</br>
<script type="text/javascript">

var ie = IeVersion();

document.write("IsIE: " + ie.IsIE + "</br>");
document.write("TrueVersion: " + ie.TrueVersion + "</br>");
document.write("ActingVersion: " + ie.ActingVersion + "</br>");
document.write("CompatibilityMode: " + ie.CompatibilityMode + "</br>");

</script>
</body>
</html>

source: Detect IE10 compatibility mode

IE11 detect whether compatibility view is ON via javascript

7 Answers