Category Archives: IE

X-UA-Compatible: IE=Edge


Imagine for an Enterprise there is global policy to use IE9 or latest version of IE in the compatibility mode like IE7, IE8 etc. But there is requirement for particular app you need to run in the Native IE9 mode or with latest IE version. This is where the X-UA-Compatible: IE=Edge Http Header comes in handy. It will ask the IE to run with latest version. This Http header can be configured in run with compatibility modes as well. Here are the possible display modes and their corresponding value to be set for the “X-UA-Compatible” meta element (or for the same custom HTTP Header)

Emulate IE8 mode  –>  IE=EmulateIE8
Emulate IE7 mode  –>  IE=EmulateIE7
IE5 mode                  –>  IE=5
IE7 mode                 –>   IE=7.5
IE8 mode                 –>   IE=8
Edge mode              –>   IE=Edge

Web Developers and Site Administrators can configure IIS and their sites. This is done by adding a custom HTTP Header to the IIS and the website web.config or to add a meta tag to specific pages.

Add the custom HTTP response header in IIS– To add a custom HTTP response header at the Web site level, at the folder level, or at the virtual directory level in IIS, follow the steps for the version of IIS that you are using.

IIS 7 on a Windows Server 2008-based Web server

  1. Start IIS Manager. To do this, click Start, click Run, type inetmgr, and then click OK.
  2. Under Connections, double-click the server that you want, and then double-click Sites.
  3. Click the Web site, the folder, or the virtual directory where you want to add the custom HTTP response header.
  4. Under <Web site name> Home, double-click HTTP Response Headers in the IIS section.
  5. Note The <Web site name> placeholder refers to the name of the Web site.
  6. Under Actions, click Add.
  7. In the Name box, type X-UA-Compatible.
  8. In the Value box, type IE=Edge.
  9. Click OK.

Add the custom HTTP response header in the Web.config file

To add this header to the Web.config file, create or revise the Web.config file as follows.

<clear />
<add name=”X-UA-Compatible” value=”IE=Edge” />

Web Page level

It can be done by adding the following meta tag to the header of each webpage you want to use compatibility mode

<!– Mimic Internet Explorer 9 –>
<meta http-equiv=”X-UA-Compatible” content=”IE=Edge” >
<title>My webpage</title>