Certain blocking APIs spin up nested message loops. Invoking those APIs during microtask execution has undesirable effects, e.g., it is possible that events are dispatched during microtasks. Those APIs currently are alert, prompt, confirm, print, and send() on synchronous XHRs.


Status in Chromium


Removed (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.

  • Positive
  • No signal
  • No signal
  • No signals


Last updated on 2020-11-09