HTML Guides for IE=edge
Learn how to identify and fix common HTML validation errors flagged by the W3C Validator — so your pages are standards-compliant and render correctly across every browser. Also check our Accessibility Guides.
The X-UA-Compatible meta tag was originally introduced to control which rendering engine Internet Explorer would use to display a page. Developers could force IE to emulate older versions (e.g., IE=7, IE=9) or use the latest available engine with IE=edge. The value IE=edge,chrome=1 was also commonly used to activate the Google Chrome Frame plugin, which allowed Internet Explorer to use Chrome’s rendering engine instead.
The HTML specification now only permits the value IE=edge for this meta tag. Other values are considered invalid for several reasons:
- Google Chrome Frame is discontinued. The chrome=1 directive targeted a plugin that was retired in February 2014 and is no longer supported by any browser.
- Legacy IE rendering modes are obsolete. Internet Explorer itself has been retired, making emulation modes like IE=EmulateIE7 or IE=9 pointless.
- Standards compliance. The WHATWG HTML living standard explicitly requires the content attribute value to be IE=edge when http-equiv="X-UA-Compatible" is used.
In practice, since all modern browsers use their latest rendering engine by default, this meta tag has little functional impact today. If your site no longer needs to support Internet Explorer at all, you can safely remove the tag entirely. If you choose to keep it — for example, in environments where legacy IE browsers might still access your site — ensure the value is exactly IE=edge.
Examples
Invalid: Using chrome=1 with IE=edge
This was a common pattern when Google Chrome Frame was active, but it now triggers a validation error:
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">Invalid: Using a legacy IE rendering mode
Forcing a specific IE version is no longer valid:
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7">Invalid: Specifying a particular IE version
<meta http-equiv="X-UA-Compatible" content="IE=9">Valid: Using IE=edge
The only accepted value is IE=edge:
<meta http-equiv="X-UA-Compatible" content="IE=edge">Valid: Removing the tag entirely
If you don’t need Internet Explorer compatibility, the simplest fix is to remove the meta tag altogether. A minimal valid document without it:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>My Page</title>
</head>
<body>
<p>Hello, world!</p>
</body>
</html>
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