The features() method of the FeaturePolicy interface returns a list of names of all features supported by the User Agent. Feature whose name appears on the list might not be allowed by the Permissions Policy of the current execution context and/or might not be accessible because of user's permissions.

None.

A list of strings that represent names of all Permissions Policy directives supported by the user agent.

The following example logs all the supported directives in the console.

// Get the FeaturePolicy object
const featurePolicy = document.featurePolicy;

// Retrieve the list of all supported Permissions Policy directives
const supportedDirectives = featurePolicy.features();

// Print out each directive into the console
for (const directive of supportedDirectives) {
  console.log(directive);
}