Feature-Policy: battery

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

The HTTP Feature-Policy header battery directive controls whether the current document is allowed to gather information about the battery of the device through the BatteryManager interface obtained via Navigator.getBattery().

Syntax

Feature-Policy: battery <allowlist>;
<allowlist>

An allowlist is a list of origins that takes one or more of the following values, separated by spaces:

  • *: The feature will be allowed in this document, and all nested browsing contexts (iframes) regardless of their origin.
  • 'self': The feature will be allowed in this document, and in all nested browsing contexts (iframes) in the same origin.
  • 'src': (In an iframe allow attribute only) The feature will be allowed in this iframe, as long as the document loaded into it comes from the same origin as the URL in the iframe's src attribute.
    The 'src' origin is used in the iframe allow attribute only, and is the default allowlist value. 
  • 'none': The feature is disabled in top-level and nested browsing contexts.
  • <origin(s)>: The feature is allowed for specific origins (for example, https://example.com). Origins should be separated by a space.

The values * (enable for all origins) or 'none' (disable for all origins) may only be used alone, while 'self' and 'src' may be used with one or more origins.

Features are each defined to have a default allowlist, which is one of:

  • *: The feature is allowed by default in top-level browsing contexts and all nested browsing contexts (iframes).
  • 'self': The feature is allowed by default in top-level browsing contexts and in nested browsing contexts (iframes) in the same origin. The feature is not allowed in cross-origin documents in nested browsing contexts.
  • 'none': The feature is disabled in top-level and nested browsing contexts.

Default policy

The default value is 'self'.

Specifications

Specification Status Comment
Permissions Policy Editor's Draft Initial definition.
Battery Status API
The definition of 'Feature Policy integration' in that specification.
Candidate Recommendation

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
battery
Experimental
Chrome No support No
Notes
No support No
Notes
Notes Will be implemented, see bug 1007264.
Edge No support No
Notes
No support No
Notes
Notes Will be implemented, see bug 1007264.
Firefox No support NoIE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support No
Notes
No support No
Notes
Notes Will be implemented, see bug 1007264.
Firefox Android No support NoOpera Android No support NoSafari iOS No support NoSamsung Internet Android No support No

Legend

No support  
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
See implementation notes.
See implementation notes.

See also