Sec-CH-UA-Mobile

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 header name Yes (Sec- prefix)

Syntax

http
Sec-CH-UA-Mobile: <boolean>

Directives

<boolean>

?1 indicates that the user-agent prefers a mobile experience (true). ?0 indicates 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:

http
Sec-CH-UA-Mobile: ?0

A browser on a mobile device would usually send requests with the following header:

http
Sec-CH-UA-Mobile: ?1

Specifications

Specification
User-Agent Client Hints
# sec-ch-ua-mobile

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Sec-CH-UA-Mobile request header
Experimental

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