Detect IE (up to version 12 and Edge)

Detect IE (up to version 12 and Edge).js

// detect IE
var IEversion = detectIE();

if (IEversion !== false) {
    // document.getElementById('result').innerHTML = 'IE ' + IEversion;
    document.getElementsByTagName("body")[0].classList.add("ie");
    document.getElementsByTagName("body")[0].classList.add("ie" + IEversion);
} else {
    // document.getElementById('result').innerHTML = 'NOT IE';
}

// add details to debug result
// document.getElementById('details').innerHTML = window.navigator.userAgent;

/**
 * detect IE
 * returns version of IE or false, if browser is not Internet Explorer
 */
function detectIE() {
    var ua = window.navigator.userAgent;

    // Test values; Uncomment to check result …

    // IE 10
    // ua = 'Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)';

    // IE 11
    // ua = 'Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko';

    // IE 12 / Spartan
    // ua = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.71 Safari/537.36 Edge/12.0';

    // Edge (IE 12+)
    // ua = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2486.0 Safari/537.36 Edge/13.10586';

    var msie = ua.indexOf('MSIE ');
    if (msie > 0) {
        // IE 10 or older => return version number
        return parseInt(ua.substring(msie + 5, ua.indexOf('.', msie)), 10);
    }

    var trident = ua.indexOf('Trident/');
    if (trident > 0) {
        // IE 11 => return version number
        var rv = ua.indexOf('rv:');
        return parseInt(ua.substring(rv + 3, ua.indexOf('.', rv)), 10);
    }

    var edge = ua.indexOf('Edge/');
    if (edge > 0) {
        // Edge (IE 12+) => return version number
        return parseInt(ua.substring(edge + 5, ua.indexOf('.', edge)), 10);
    }

    // other browser
    return false;
}