Accept-CH
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The Accept-CH
header may be set by a server to specify
which client hints headers a client
should include in subsequent requests.
Header type | Response header |
---|---|
Forbidden header name | no |
CORS-safelisted response header | no |
Note: Client hints are accessible only on secure origins (via TLS).
Accept-CH
(and Accept-CH-Lifetime
) headers should be persisted for all secure requests to ensure client hints are sent reliably.
Syntax
http
Accept-CH: <comma separated list of client hint headers>
Examples
http
Accept-CH: Viewport-Width, Width
Vary: Viewport-Width, Width
Note: Remember to vary the response based on the accepted client hints.
Specifications
Specification |
---|
HTTP Client Hints # section-3.1 |
Browser compatibility
BCD tables only load in the browser