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). The Accept-CH header 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
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