CORS · Response header
Access-Control-Allow-Headers
Which request headers may be used in the actual cross-origin request.
What is Access-Control-Allow-Headers?
Sent in preflight responses to whitelist non-simple request headers (like Authorization, Content-Type: application/json).
Typical usage
Set on OPTIONS preflight responses.
Examples
Access-Control-Allow-Headers: Content-Type, AuthorizationSpecification
Fetch Standard §CORS
Frequently asked questions
What is the Access-Control-Allow-Headers HTTP header?
Sent in preflight responses to whitelist non-simple request headers (like Authorization, Content-Type: application/json).
Is Access-Control-Allow-Headers a request or response header?
Access-Control-Allow-Headers is a response header — the server sends it to the client. Set on OPTIONS preflight responses.
What does a Access-Control-Allow-Headers header look like?
A typical Access-Control-Allow-Headers header looks like: Access-Control-Allow-Headers: Content-Type, Authorization.
Related headers
Access-Control-Allow-Origin
Which origins may read this response cross-origin.
Access-Control-Allow-Methods
Which HTTP methods are allowed on the cross-origin resource.
Access-Control-Allow-Credentials
Whether cookies and Authorization can be sent cross-origin.
Access-Control-Max-Age
How long the browser may cache the preflight response.
Origin
The origin (scheme + host + port) of the request.