Web developers are able to register or unregister custom schemes, but there is no way to verify that the custom schemes are well registered. NavigatorContentUtils.IsProtocolHandlerRegistered is a way to check whether a custom scheme is registered.


Specification link

Specification being incubated in a Community Group

Status in Chromium


No longer pursuing (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • Positive
  • No signal
  • Positive



It was added to W3C HTML 5.2 version: https://www.w3.org/TR/html52/webappapis.html#dom-navigatorcontentutils-isprotocolhandlerregistered But, the latest WHATWG spec removed the feature: https://html.spec.whatwg.org/multipage/system-state.html#custom-handlers because no browsers have supported the feature.

Search tags

custom handlers, navigator content utils, registerProtocolHandler, isProtocolHandlerRegistered,

Last updated on 2021-10-25