DISCLAIMER: this post is older than one year and may not be up to date with latest WordPress version.

To ensure maximum cross-browser compatibility on your blog theme, you have to be able to detect the browser used by the visitor. Sure, you can use conditionnal comments, but WordPress itself can detect client browser. Let’s see how to do.

Simply paste the code below in your functions.php file:

function browser_body_class($classes) {
	global $is_lynx, $is_gecko, $is_IE, $is_opera, $is_NS4, $is_safari, $is_chrome, $is_iphone;

	if($is_lynx) $classes[] = 'lynx';
	elseif($is_gecko) $classes[] = 'gecko';
	elseif($is_opera) $classes[] = 'opera';
	elseif($is_NS4) $classes[] = 'ns4';
	elseif($is_safari) $classes[] = 'safari';
	elseif($is_chrome) $classes[] = 'chrome';
	elseif($is_IE) $classes[] = 'ie';
	else $classes[] = 'unknown';

	if($is_iphone) $classes[] = 'iphone';
	return $classes;

Once you saved the file, the function will automatically add a CSS class to the body tag, as shown in the exemple below:

<body class="home blog logged-in safari">

That’s all. You just have to take your stylesheet, and add some browser-specific styles!

Credits goes to Nathan Rice for this awesome trick!


  1. This is a great tip. I wasn’t aware that WP had the is_XX to check for browsers. Thanks.

  2. simple and easy tip but with great results.
    Thanks for this one!

  3. This can detect any mobile device?

Leave a Comment

Your email address will not be published. Required fields are marked *