Sec-CH-UA-Platform

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-Platform request header is a user agent client hint which provides the platform or operating system on which the user agent is running. For example: "Windows" or "Android".

Sec-CH-UA-Platform 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-Platform: <platform>

Directives

<platform>

One of the following strings: "Android", "Chrome OS", "Chromium OS", "iOS", "Linux", "macOS", "Windows", or "Unknown".

Examples

Using Sec-CH-UA-Platform

As Sec-CH-UA-Platform is a low entropy hint it is typically sent in all requests. A browser running on a macOS computer might add the following header to all requests.

http
Sec-CH-UA-Platform: "macOS"

Specifications

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

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-Platform 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