Accept-CH

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The HTTP Accept-CH response header may be set by a server to specify which client hint headers should be included by the client in subsequent requests. To ensure client hints are sent reliably, the Accept-CH header should be persisted for all secure requests.

Header type Response header
Forbidden header name No
CORS-safelisted response header No

Syntax

http
Accept-CH: <client-hints-headers>

// Client hint headers in a comma-separated list
Accept-CH: <ch-header-one>, <ch-header-two>

Examples

Client hint response headers

The following response headers indicate that the server accepts Viewport-Width and Width device client hints in subsequent requests. The Vary header indicates which values were used to vary the response based on the accepted client hints.

http
Accept-CH: Viewport-Width, Width
Vary: Viewport-Width, Width

Specifications

Specification
HTTP Client Hints
# section-3.1

Browser compatibility

BCD tables only load in the browser

See also