Detect IE version (prior to v9) in JavaScript

Question

I want to bounce users of our web site to an error page if they\'re using a version of Internet Explorer prior to v9. It\'s just not worth our time and money to

Answer 1

I realise I am a little late to the party here, but I had been checking out a simple one line way to provide feedback on whether a browser is IE and what version from 10 down it was. I haven't coded this for version 11, so perhaps a little amendment will be needed for that.

However this is the code, it works as an object that has a property and a method and relies on object detection rather than scraping the navigator object (which is massively flawed as it can be spoofed).

var isIE = { browser:/*@cc_on!@*/false, detectedVersion: function () { return (typeof window.atob !== "undefined") ? 10 : (typeof document.addEventListener !== "undefined") ? 9 : (typeof document.querySelector !== "undefined") ? 8 : (typeof window.XMLHttpRequest !== "undefined") ? 7 : (typeof document.compatMode !== "undefined") ? 6 : 5; } };

The usage is isIE.browser a property that returns a boolean and relies on conditional comments the method isIE.detectedVersion() which returns a number between 5 and 10. I am making the assumption that anything lower than 6 and you are in serious old school territory and you will something more beefy than a one liner and anything higher than 10 and you are in to newer territory. I have read something about IE11 not supporting conditional comments but I've not fully investigated, that is maybe for a later date.

Anyway, as it is, and for a one liner, it will cover the basics of IE browser and version detection. It's far from perfect, but it is small and easily amended.

Just for reference, and if anyone is in any doubt on how to actually implement this then the following conditional should help.

var isIE = { browser:/*@cc_on!@*/false, detectedVersion: function () { return (typeof window.atob !== "undefined") ? 10 : (typeof document.addEventListener !== "undefined") ? 9 : (typeof document.querySelector !== "undefined") ? 8 : (typeof window.XMLHttpRequest !== "undefined") ? 7 : (typeof document.compatMode !== "undefined") ? 6 : 5; } };

/* testing IE */

if (isIE.browser) {
  alert("This is an IE browser, with a detected version of : " + isIE.detectedVersion());
}