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Access-Control-Allow-Origin

The Access-Control-Allow-Origin response header indicates whether the response can be shared with resources with the given origin.

Header type Response header
Forbidden header name no

Syntax

Access-Control-Allow-Origin: *
Access-Control-Allow-Origin: <origin>

Directives

*
For requests without credentials, the server may specify "*" as a wildcard, thereby allowing any origin to access the resource.
<origin>
Specifies a URI that may access the resource.

Examples

To allow any resource to access your resource, you can specify:

Access-Control-Allow-Origin: *

To allow https://developer.mozilla.org to access your resource, you can specify:

Access-Control-Allow-Origin: https://developer.mozilla.org

CORS and caching

If the server specifies an origin host rather than "*", then it must also include Origin in the Vary response header to indicate to clients that server responses will differ based on the value of the Origin request header.

Access-Control-Allow-Origin: https://developer.mozilla.org
Vary: Origin

Specifications

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

Browser compatibility

FeatureChromeFirefoxEdgeInternet ExplorerOperaSafari
Basic Support43.51210124
FeatureAndroidChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic Support2.1(Yes)(Yes)1.0(Yes)123.2

See also

Document Tags and Contributors

 Contributors to this page: fscholz, teoli
 Last updated by: fscholz,