Permissions-Policy: ch-ua-high-entropy-values directive
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The HTTP Permissions-Policy header ch-ua-high-entropy-values directive controls whether or not the document is permitted to use the NavigatorUAData.getHighEntropyValues() method to retrieve high-entropy user-agent data.
If the permission is not allowed, the method will only return the brands, mobile, and platform low-entropy data.
Syntax
Permissions-Policy: ch-ua-high-entropy-values=<allowlist>;
<allowlist>-
A list of origins for which permission is granted to use the feature. See
Permissions-Policy> Syntax for more details.
Default policy
The default allowlist for ch-ua-high-entropy-values is *.
Examples
Restricting high-entropy data to specific origins
The following policy would only allow the current origin and two other specific origins to retrieve high-entropy data.
Permissions-Policy: ch-ua-high-entropy-values=("self https://a.example.com" "https://b.example.com")
You could then embed one of the two other origins:
<iframe src="https://a.example.com" allow="ch-ua-high-entropy-values"></iframe>