FeaturePolicy.allowsFeature()

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The allowsFeature() method of the FeaturePolicy interface enables introspection of individual directives of the Feature Policy it is run on. It returns a Boolean that is true if and only if the specified feature is allowed in the specified context (or the default context if no context is specified).

Syntax

const allowed = FeaturePolicy.allowsFeature(<feature>)

or

const allowed = FeaturePolicy.allowsFeature(<feature>, <origin>)

Parameters

Feature name

A specific feature name must be specified.

Origin name

Optionally, an origin can be specified. If it is omitted the bedault origin is used.

Return value

A Boolean that is true if and only if the feature is allowed.

Example

The followin example queries whether or not the document is allowed to use camera API by the Feature Policy. Please note that Camera API might be restricted by the Permissions API, if the user did not grant the corrsponding permission yet.

// First, get the Feature Policy object
const featurePolicy = document.featurePolicy

// Then query feature for specific 
const allowed = featurePolicy.allowsFeature("camera")

if (allowed){
  console.log("FP allows camera.")
} else {
  console.log("FP does not allows camera.")
}

Specifications

Specification Status Comment
Feature Policy
The definition of 'allowsFeature' in that specification.
Editor's Draft Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
allowsFeature
Experimental
Chrome Full support 74
Full support 74
No support 69 — 73
Disabled
Disabled From version 69 until version 73 (exclusive): this feature is behind the #enable-experimental-productivity-features preference (needs to be set to Enabled). To change preferences in Chrome, visit chrome://flags.
Edge No support NoFirefox Full support 65
Disabled
Full support 65
Disabled
Disabled From version 65: this feature is behind the dom.security.featurePolicy.webidl.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 62
Full support 62
No support 56 — 62
Disabled
Disabled From version 56 until version 62 (exclusive): this feature is behind the #enable-experimental-productivity-features preference (needs to be set to Enabled).
Safari No support NoWebView Android Full support 74Chrome Android Full support 74
Full support 74
No support 69 — 74
Disabled
Disabled From version 69 until version 74 (exclusive): this feature is behind the #enable-experimental-productivity-features preference (needs to be set to Enabled). To change preferences in Chrome, visit chrome://flags.
Firefox Android Full support 65
Disabled
Full support 65
Disabled
Disabled From version 65: this feature is behind the dom.security.featurePolicy.webidl.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 48
Disabled
Full support 48
Disabled
Disabled From version 48: this feature is behind the #enable-experimental-productivity-features preference (needs to be set to Enabled).
Safari iOS No support NoSamsung Internet Android ?

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
User must explicitly enable this feature.
User must explicitly enable this feature.

Document Tags and Contributors

Contributors to this page: bershanskiy
Last updated by: bershanskiy,