htmlinternet-explorerx-ua-compatible

"X-UA-Compatible" content="IE=9; IE=8; IE=7; IE=EDGE"

<meta http-equiv="X-UA-Compatible" content="IE=9; IE=8; IE=7; IE=EDGE" />

  1. Actually what is the meaning of this statement ?

  2. Some of the examples use , to separate versions of IE, while some use ;; which is correct?

  3. The order IE=9; IE=8; IE=7; IE=EDGE has some importance, I wish to know that.

Edit: I am using <!DOCTYPE html>

Solution

  • If you support IE, for versions of Internet Explorer 8 and above, this:

    <meta http-equiv="X-UA-Compatible" content="IE=9; IE=8; IE=7" />

    Forces the browser to render as that particular version's standards. It is not supported for IE7 and below.

    If you separate with semi-colon, it sets compatibility levels for different versions. For example:

    <meta http-equiv="X-UA-Compatible" content="IE=7; IE=9" />

    Renders IE7 and IE8 as IE7, but IE9 as IE9. It allows for different levels of backwards compatibility. In real life, though, you should only chose one of the options:

    <meta http-equiv="X-UA-Compatible" content="IE=8" />

    This allows for much easier testing and maintenance. Although generally the more useful version of this is using Emulate:

    <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8" />

    For this:

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

    It forces the browser the render at whatever the most recent version's standards are.

    For more information, there is plenty to read about on MSDN,