When setting Internet Explorer's
header, you can tell if it worked because the compatibility view button disappears. This indicates IE is using
your chosen value, whether that's
ie=7 for "IE7 Standards" mode,
"Industry Standards" mode (as close as IE8 gets, anyway), or
Google Chrome Frame.
X-UA-Compatibleheader (or meta tag) properly set.
With the introduction of Chrome Frame for IE, many webmasters would like their sites to load in Chrome Frame if
available, and IE8 Standards mode otherwise. Some advise using two meta tags to accomplish this, with the first
chrome=1 and the second specifying
ie=8. However, according to Microsoft's
documentation, IE completely ignores any
X-UA-Compatible header beyond the first on a page, so
if your visitor does not have Chrome Frame installed, your site will probably be viewed according to your
DOCTYPE, which may be IE8 Standards mode, IE7 Standards mode, or IE5 (quirks) mode. Also,
the visitor's own Compatibility View setting can override your
The proper way to specify more than one compatibility mode is to use one meta tag, with the values separated by semicolons:
<!-- render in Chrome Frame if available, or IE8 Industry Standard mode otherwise --> <meta http-equiv="X-UA-Compatible" content="chrome=1;ie=8">
As always, it's best to specify a
to ensure cross-browser compatibility, but using Microsoft's
X-UA-Compatible meta tag
correctly gives you an edge in the battle against IE's ever unpredictable Quirks Mode.