This function upgrades undefined custom elements explicitly. If a custom element is created with the innerHTML setter and its parent node is not connected to a document, the custom element is not upgraded until it's connected. Upgrading such elements explicitly allows developers to handle them in a single way regardless of connectedness.


Specification link

Specification being incubated in a Community Group

Status in Chromium


Enabled by default (tracking bug)

Consensus & Standardization

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

  • No signal
  • Positive
  • Positive

Last updated on 2022-01-14