Breaking Some non-standard events can no longer be created


Categories: DOM

Releases: Firefox 74, Firefox 78 ESR


Firefox 74 has removed the support for creating several non-standard events with document.createEvent(). These event types include:

  • KeyEvents (standard equivalent: KeyboardEvent)
  • MouseScrollEvents
  • ScrollAreaEvent
  • TimeEvent

Update: One minor website is affected by this change.

How can I test this?

This change can be tested with the compatibilty checker in our Firefox Developer Tools extension. Get it today!