Accept-CH header
Secure context: This feature is available only insecure contexts (HTTPS), in some or allsupporting browsers.
The HTTPAccept-CHresponse header may be set by a server to specify whichclient hint headers should be included by the client in subsequent requests.To ensure client hints are sent reliably, theAccept-CH header should be persisted for all secure requests.
| Header type | Response header |
|---|---|
| CORS-safelisted response header | No |
Syntax
http
Accept-CH: <client-hints-headers>// Client hint headers in a comma-separated listAccept-CH: <ch-header-one>, <ch-header-two>Examples
Client hint response headers
The following response headers indicate that the server acceptsViewport-Width andWidthdevice client hints in subsequent requests.TheVary header indicates which values were used tovary the response based on the accepted client hints.
http
Accept-CH: Viewport-Width, WidthVary: Viewport-Width, WidthSpecifications
| Specification |
|---|
| HTTP Client Hints # section-3.1 |