Sec-CH-UA-Mobile header
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The HTTP Sec-CH-UA-Mobile request header is a user agent client hint which indicates whether the browser is on a mobile device.
It can also be used by a desktop browser to indicate a preference for a "mobile" user experience.
Sec-CH-UA-Mobile is a low entropy hint.
Unless blocked by a user agent permission policy, it is sent by default, without the server opting in by sending Accept-CH.
| Header type | Request header, Client hint |
|---|---|
| Forbidden request header | Yes (Sec- prefix) |
Syntax
Sec-CH-UA-Mobile: <boolean>
Directives
<boolean>-
?1indicates that the user-agent prefers a mobile experience (true).?0indicates that user-agent does not prefer a mobile experience (false).
Examples
Using Sec-CH-UA-Mobile
As Sec-CH-UA-Mobile is a low entropy hint it is typically sent in all requests.
A desktop browser would usually send requests with the following header:
Sec-CH-UA-Mobile: ?0
A browser on a mobile device would usually send requests with the following header:
Sec-CH-UA-Mobile: ?1
Specifications
| Specification |
|---|
| User-Agent Client Hints # sec-ch-ua-mobile |
Browser compatibility
| desktop | mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sec-CH-UA-Mobile request header
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Legend
Tip: you can click/tap on a cell for more information.
- Full support
- Full support
- No support
- No support
- Experimental. Expect behavior to change in the future.
See also
- Client hints
- User-Agent Client Hints API
Accept-CH- HTTP Caching: Vary and
Varyheader - Improving user privacy and developer experience with User-Agent Client Hints (developer.chrome.com)