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Sec-CH-UA-Mobile header

files/en-us/web/http/reference/headers/sec-ch-ua-mobile/index.md

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{{SeeCompatTable}}{{SecureContext_Header}}

The HTTP Sec-CH-UA-Mobile {{Glossary("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 {{HTTPHeader("Accept-CH")}}.

<table class="properties"> <tbody> <tr> <th scope="row">Header type</th> <td> {{Glossary("Request header")}}, <a href="/en-US/docs/Web/HTTP/Guides/Client_hints">Client hint</a> </td> </tr> <tr> <th scope="row">{{Glossary("Forbidden request header")}}</th> <td>Yes (<code>Sec-</code> prefix)</td> </tr> </tbody> </table>

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

{{Specifications}}

Browser compatibility

{{Compat}}

See also