Detect IE Version

getIEVersion.js

// Looks at User Agent to determine if IE and which version
function GetIEVersion() {
  var sAgent = window.navigator.userAgent;
  var idx = sAgent.indexOf("MSIE");
  var versionNumber = 0;

  // If IE, return version number.
  if (idx) {
    try {
      versionNumber = parseInt(sAgent.substring(idx+ 5, sAgent.indexOf(".", idx)));
    } catch (e) {
      // swallow it
    }
  }

  // If IE 11 then look for "Trident" in user agent string.
  if (!versionNumber && !!navigator.userAgent.match(/trident/gi)) {
    versionNumber = 11;
  }

  // If IE Edge then look for "Edge" in user agent string.
  if (!versionNumber && !!navigator.userAgent.match(/edge/gi)) {
  versionNumber = 13;
  }
  
  return versionNumber;
}

getIeVersion.min.js

function GetIEVersion(){var t=window.navigator.userAgent,n=t.indexOf("MSIE"),e=0;if(n)try{e=parseInt(t.substring(n+5,t.indexOf(".",n)))}catch(t){}return!e&&navigator.userAgent.match(/trident/gi)&&(e=11),!e&&navigator.userAgent.match(/edge/gi)&&(e=13),e}