Custom Elements V0

Method for registering (creating) custom elements in script. The spec is superceded by Custom Elements V1 and Blink is the only engine that implements V0 APIs.


Edge's signal should be treated for implementing V1 spec. Firefox once implemented behind the flag, but removed in favor of V1 APIs. Safari did not implement Custom Elements V0 spec, but already implemented V1 APIs and shipped it.



Working draft or equivalent

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 33
  • Chrome for Android release 33
  • Android WebView release 33
  • Opera release 20
  • Opera for Android release 20

Consensus & Standardization

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


Last updated on 2018-02-02