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http header

Accept-CH header

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Secure context

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](https://developer.mozilla.org/en-US/docs/Glossary/Response%20header)
[CORS-safelisted response header](https://developer.mozilla.org/en-US/docs/Glossary/CORS-safelisted%20response%20header) No

Syntax

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 Sec-CH-Viewport-Width and Sec-CH-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.

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

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also