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/HTTP

Access-Control-Allow-Headers

The Access-Control-Allow-Headers response header is used in response to a preflight request to indicate which HTTP headers will be available via Access-Control-Expose-Headers when making the actual request.

The simple headers, Accept, Accept-Language, Content-Language, Content-Type (but only with a MIME type of its parsed value (ignoring parameters) of either application/x-www-form-urlencoded, multipart/form-data, or text/plain), are always available and don't need to be listed by this header.

This header is required if the request has an Access-Control-Request-Headers header.

Syntax

Access-Control-Allow-Headers: <header-name>, <header-name>, ...

Directives

<header-name>
Comma-delimited list of the supported request headers.

Examples

Access-Control-Allow-Headers: X-Custom-Header

Specifications

Specification Status Comment
Fetch
The definition of 'Access-Control-Allow-Headers' in that specification.
Living Standard Initial definition.

Browser compatibility

Feature Chrome Firefox Edge Internet Explorer Opera Safari
Basic Support 4 3.5 12 10 12 4
Feature Android Chrome for Android Edge mobile Firefox for Android IE mobile Opera Android iOS Safari
Basic Support 2.1 (Yes) (Yes) 1.0 (Yes) 12 3.2

Compatibility notes

  • The wildcard value (*) that is mentioned in the latest specification, is not yet implemented in browsers:

See also

© 2005–2017 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Headers