index.md

---

title: Access-Control-Expose-Headers
slug: Web/HTTP/Headers/Access-Control-Expose-Headers
browser-compat: http.headers.Access-Control-Expose-Headers

---

{{HTTPSidebar}}

The Access-Control-Expose-Headers response header allows a server to indicate which response headers should be made available to scripts running in the browser, in response to a cross-origin request.

Only the {{Glossary("CORS-safelisted response header", "CORS-safelisted response headers")}} are exposed by default. For clients to be able to access other headers, the server must list them using the Access-Control-Expose-Headers header.

Header type	{{Glossary("Response header")}}
{{Glossary("Forbidden header name")}}	no

Syntax

Access-Control-Expose-Headers: [<header-name>[, <header-name>]*]
Access-Control-Expose-Headers: *

Directives

• <header-name>

  • : A list of zero or more comma-separated header names that clients are allowed to access from a response. These are in addition to the {{Glossary("CORS-safelisted response header", "CORS-safelisted response headers")}}.

• * (wildcard)

  • : The value "*" only counts as a special wildcard value for requests without credentials (requests without HTTP cookies or HTTP authentication information). In requests with credentials, it is treated as the literal header name "*" without special semantics.

Examples

The {{Glossary("CORS-safelisted response header", "CORS-safelisted response headers")}} are: {{HTTPHeader("Cache-Control")}}, {{HTTPHeader("Content-Language")}}, {{HTTPHeader("Content-Length")}}, {{HTTPHeader("Content-Type")}}, {{HTTPHeader("Expires")}}, {{HTTPHeader("Last-Modified")}}, {{HTTPHeader("Pragma")}}. To expose a non-CORS-safelisted response header, you can specify:

Access-Control-Expose-Headers: Content-Encoding

To additionally expose a custom header, like Kuma-Revision, you can specify multiple headers separated by a comma:

Access-Control-Expose-Headers: Content-Encoding, Kuma-Revision

For requests without credentials, a server can also respond with a wildcard value:

Access-Control-Expose-Headers: *

However, this won't wildcard the {{HTTPHeader("Authorization")}} header, so if you need to expose that, you will need to list it explicitly:

Access-Control-Expose-Headers: *, Authorization

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{HTTPHeader("Access-Control-Allow-Headers")}}

• {{HTTPHeader("Access-Control-Allow-Origin")}}