Custom Elements let web authors define their own tags. Chrome shipped an implementation based on the working draft of the spec in M33. The current editor's draft of the spec has significant updates based on web developer and implementer feedback.



Working draft or equivalent

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 54
  • Chrome for Android release 54
  • Android WebView release 54

Consensus & Standardization

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



Safari has indicated that they will not implement customized built-in elements, eg

Last updated on 2020-11-09