Sec-CH-UA-Full-Version-List

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-Full-Version-List request header is a user agent client hint which provides the user-agent's branding and full version information.

The Sec-CH-UA-Full-Version-List header provides the brand and full version information for each brand associated with the browser, in a comma-separated list.

The header may include "fake" brands in any position and with any name. This is a feature designed to prevent servers from rejecting unknown user agents outright, forcing user agents to lie about their brand identity.

Note: This is similar to Sec-CH-UA, but includes the full version number instead of the significant version number for each brand.

Header type Request header, Client hint
Forbidden header name Yes (Sec- prefix)

Syntax

A comma separated list of brands in the user agent brand list, and their associated full version number. The syntax for a single entry has the following format:

http
Sec-CH-UA-Full-Version-List: "<brand>";v="<full version>", ...

Directives

<brand>

A brand associated with the user agent, like "Chromium", "Google Chrome". This may be an intentionally incorrect brand like " Not A;Brand" or "(Not(A:Brand" (the actual value is expected change over time and be unpredictable).

<full version>

A full version number, such as 98.0.4750.0.

Description

A brand is a commercial name for the user agent like: Chromium, Opera, Google Chrome, Microsoft Edge, Firefox, and Safari. A user agent might have several associated brands. For example, Opera, Chrome, and Edge are all based on Chromium, and will provide both brands in the Sec-CH-UA-Full-Version-List header.

The header allows the server to customize its response based on both shared brands and on particular customizations in their specific respective builds.

Examples

Using Sec-CH-UA-Full-Version-List

A server requests the Sec-CH-UA-Full-Version-List header by including the Accept-CH in a response to any request from the client, using the name of the desired header as a token:

http
HTTP/1.1 200 OK
Accept-CH: Sec-CH-UA-Full-Version-List

The client may choose to provide the hint, and add the Sec-CH-UA-Full-Version-List header to subsequent requests, as shown below:

http
GET /my/page HTTP/1.1
Host: example.site

Sec-CH-UA: " Not A;Brand";v="99", "Chromium";v="98", "Google Chrome";v="98"
Sec-CH-UA-Mobile: ?0
Sec-CH-UA-Full-Version-List: " Not A;Brand";v="99.0.0.0", "Chromium";v="98.0.4750.0", "Google Chrome";v="98.0.4750.0"
Sec-CH-UA-Platform: "Linux"

Specifications

Specification
User-Agent Client Hints
# sec-ch-ua-full-version-list

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-Full-Version-List 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