Feature-Policy: usb

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

The HTTP Feature-Policy header usb directive controls whether the current document is allowed to use the WebUSB API.

Syntax

Feature-Policy: usb <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.
  • '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
Feature Policy Editor's Draft Initial definition.
WebUSB
The definition of 'Feature-Policy integration' in that specification.
Draft Default allow list is 'self'.

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
usb
Experimental
Chrome Full support 60Edge Full support 79Firefox No support NoIE No support NoOpera Full support 47Safari No support NoWebView Android Full support 60Chrome Android Full support 60Firefox Android No support NoOpera Android Full support 44Safari iOS No support NoSamsung Internet Android Full support 8.0

Legend

Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also