Accept-CH

Accept-CH

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

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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

Accept-CH: <list of client hints>

Examples

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

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
Accept-CH
46
≤79
?
?
33
?
46
46
?
33
?
5.0
Content-DPR
46
≤79
?
?
33
?
46
46
?
33
?
5.0
Device-Memory
61
≤79
?
?
48
No
61
61
?
?
No
8.0
DPR
46
≤79
?
?
33
?
46
46
?
33
?
5.0
Sec-CH-UA
89
89
No
No
75
No
89
89
No
63
No
No
Sec-CH-UA-Arch
89
89
No
No
75
No
89
89
No
63
No
No
Sec-CH-UA-Full-Version
89
89
No
No
75
No
89
89
No
63
No
No
Sec-CH-UA-Mobile
89
89
No
No
75
No
89
89
No
63
No
No
Sec-CH-UA-Model
89
89
No
No
75
No
89
89
No
63
No
No
Sec-CH-UA-Platform
89
89
No
No
75
No
89
89
No
63
No
No
Sec-CH-UA-Platform-Version
89
89
No
No
75
No
89
89
No
63
No
No
Viewport-Width
46
≤79
?
?
33
?
46
46
?
33
?
5.0
Width
46
≤79
?
?
33
?
46
46
?
33
?
5.0

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-CH