As per the spec, "The start IDL attribute must reflect the content attribute of the same name, with a default value of 1. This means that the start IDL attribute does not necessarily match the list's starting value, in cases where the start content attribute is omitted and the reversed content attribute is specified."


Editor's draft

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 62
  • Chrome for Android release 62
  • Android WebView release 62

Consensus & Standardization

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

  • Shipped/Shipping
  • Shipped/Shipping
  • No signal
  • Positive


Last updated on 2020-11-09