Detect IE version (prior to v9) in JavaScript

browser-detection, internet-explorer, javascript, user-agent

Solution

This is my preferred way of doing it. It gives maximum control. (Note: Conditional statements are only supported in IE5 - 9.)

First set up your ie classes correctly

<!DOCTYPE html>
<!--[if lt IE 7]> <html class="lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
<!--[if IE 7]>    <html class="lt-ie9 lt-ie8"> <![endif]-->
<!--[if IE 8]>    <html class="lt-ie9"> <![endif]-->
<!--[if gt IE 8]><!--> <html> <!--<![endif]-->    
<head>

Then you can just use CSS to make style exceptions, or, if you require, you can add some simple JavaScript:

(function ($) {
    "use strict";

    // Detecting IE
    var oldIE;
    if ($('html').is('.lt-ie7, .lt-ie8, .lt-ie9')) {
        oldIE = true;
    }

    if (oldIE) {
        // Here's your JS for IE..
    } else {
        // ..And here's the full-fat code for everyone else
    }

}(jQuery));

Thanks to Paul Irish.

Problem

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 support `IE pre-v9`. Users of all other non-IE browsers are fine and shouldn't be bounced. Here's the proposed code: ``` if(navigator.appName.indexOf("Internet Explorer")!=-1){ //yeah, he's using IE var badBrowser=( navigator.appVersion.indexOf("MSIE 9")==-1 && //v9 is ok navigator.appVersion.indexOf("MSIE 1")==-1 //v10, 11, 12, etc. is fine too ); if(badBrowser){ // navigate to error page } } ``` Will this code do the trick? To head off a few comments that will probably be coming my way: - Yes, I know that users can forge their `useragent` string. I'm not concerned. - Yes, I know that programming pros prefer sniffing out feature-support instead of browser-type but I don't feel this approach makes sense in this case. I already know that all (relevant) non-IE browsers support the features that I need and that all `pre-v9 IE` browsers don't. Checking feature by feature throughout the site would be a waste. - Yes, I know that someone trying to access the site using `IE v1` (or >= 20) wouldn't get 'badBrowser' set to true and the warning page wouldn't be displayed properly. That's a risk we're willing to take. - Yes, I know that Microsoft has "conditional comments" that can be used for precise browser version detection. IE no longer supports conditional comments as of `IE 10`, rendering this approach absolutely useless. Any other obvious issues to be aware of?

Original source

Related problems