How to Detect Internet Explorer Versions Prior to v9 in JavaScript

Introduction

Supporting outdated browser versions can be a challenge for web developers. Particularly concerning is Internet Explorer (IE) pre-v9, which lacks essential modern features. This article explores a reliable method for detecting IE versions prior to v9 using JavaScript, addressing concerns and providing an alternative solution.

Proposed Code

The original code snippet proposes detecting IE pre-v9 using the navigator object's appName and appVersion properties. However, this approach has limitations:

• It assumes the user agent string is genuine, which is not always the case.
• It requires checking multiple conditions to determine the browser version.

Alternative Solution

A more reliable approach involves using conditional comments in the HTML markup to create IE-specific class names. This method allows for granular browser detection and can be easily integrated with CSS or JavaScript.

CSS Approach:

JavaScript Approach:

(function ($) {
    var oldIE = $('html').is('.lt-ie7, .lt-ie8, .lt-ie9');
    if (oldIE) {
        // IE-specific JavaScript
    } else {
        // Code for other browsers
    }
}(jQuery));

Conclusion

Using conditional comments to detect IE versions prior to v9 is a reliable and versatile approach. This method provides precise browser identification and allows for easy implementation through CSS or JavaScript. By leveraging this technique, developers can effectively handle outdated browsers and improve user experience.