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)
Sec-CH-UA-Mobile: <boolean><boolean>?1 indicates that the user-agent prefers a mobile experience (true). ?0 indicates that user-agent does not prefer a mobile experience (false).
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: ?0A browser on a mobile device would usually send requests with the following header:
Sec-CH-UA-Mobile: ?1