Posted 25 March 2009, when IE8 was in the wild and its new rendering engine threatened to break pages tuned for IE7. Updated in 2026 as a short retrospective: nobody should ship this meta tag today, but you will still meet it in old codebases.
IE8 shipped with a standards-compliant rendering engine, and that was exactly the problem: pages that had been “fixed” against IE7’s quirks suddenly looked broken. Microsoft’s escape hatch was a single meta tag telling IE8 to keep rendering in IE7 mode:
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />That one line — or the equivalent HTTP header — forced the old document mode, and the Compat View button in the address bar let users trigger the same thing per site. The official account of how IE chose between these document modes survives in Microsoft’s [MS-IEDOCO] specification.
What happened next
The tag was meant as a one-generation bridge but outlived IE8 by years; IE=edge in the same header later became the standard way to stop intranet pages from silently dropping into Compatibility View. IE itself is gone: desktop versions older than IE 11 lost support in January 2016, IE 11 was retired on 15 June 2022, and Microsoft’s Lifecycle FAQ now points legacy-IE questions at IE mode in Microsoft Edge.
If you find EmulateIE7 in a codebase today, delete it and let the page render in standards mode — every browser that matters has been evergreen for a decade. If a legacy intranet app genuinely needs old IE behaviour, that is what IE mode in Edge is for; a meta tag emulating a 2006 browser is not.