Configuring Your Server for IE 8

Originally posted on Web Pro World.

Microsoft Internet Explorer 8 is designed to be more standards compliant than previous versions. As a result, certain hacks in web sites can cause those sites to display incorrectly in Internet Explorer 8. This can be addressed by forcing browsers to render your site in what is called "compatibility mode". The following instructions detail how to enable compatibility mode site wide, if your site is hosted on an Apache server.

Setting Compatibility Mode for all visitors on Apache

Enabling compatibility mode on an Apache server requires the ability to create and edit .htaccess files, and mod_headers must be installed on the server. Most shared and dedicated hosting plans should allow this.

Simply add the following line to your .htaccess file.
Code:

Header set X-UA-Compatible "IE=EmulateIE7"

Setting Compatibility Mode for everyone but the webmaster

If you will be testing your site, and want your own browser to work without compatibility mode, you can specify certain IP addresses that will not be shown the header.

First, create a list of IP addresses that should not have compatibility mode. Add the following line to the .htaccess file, changing 1.2.3.4 to the appropriate address. Each IP address would require a seperate line.

SetEnvIf Remote_Addr 1.2.3.4 webmaster

This assigns the code "webmaster" to each specified IP address. Now, you would add the compatability header, telling it to display if the visitor has not been given the "webmaster" code. This is done by adding the following line to the .htaccess file after the lines you added above.

Header set X-UA-Compatible "IE=EmulateIE7" env=!webmaster

Everyone not from the specified IP address will be put in compatibility mode by default. Those visiting the site from the specified IP address(es) can enable compatibility if they want, but it will be disabled by default.

Setting Compatibility Mode on IIS 7

If you have administrative access to your IIS server, you can add new headers by following the instructions here: IIS 7.0: Add a Custom HTTP Response Header

The name you need to specify is "X-UA-Compatible" and the value is "IE=EmulateIE7" (without the quotes).

Setting Compatibility Mode on other platforms

If you can not use the above method for any reason, you can add compatibility mode to each page by adding the following meta tag:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />