How we built it

Prefixed Shadow DOM (deprecated)

Enables DOM tree encapsulation. Without it, widgets may inadvertently break pages by using conflicting CSS selectors, class or id names, or JavaScript variables.


This old and prefixed implementation is being deprecated, please watch out for deprecation warnings in the devtools console. We have enabled an unprefixed modern Shadow DOM implementation in M35 (see the latest spec and polymer-dev for additional details on what changed since then) Updated IE views based on ("Under consideration"). Latest spec: see also for the styling aspects.


Working draft or equivalent

Status in Chromium

Deprecated (launch bug) in:

  • Chrome for desktop release 35
  • Opera release 22
  • Opera for Android release 22

Consensus & Standardization


Last updated on 2014-04-03