api.MutationEvent - Safari no longer supports mutation events

[lukewarlow]

What type of issue is this?

Incorrect support data (example: BrowserX says "86" but support was added in "40")

What information was incorrect, unhelpful, or incomplete?

Safari has recently removed support for mutation events. I cannot confirm the exact version but it's removed in latest preview release and in 26 beta. I guess it would be removed in 18.4 at the earliest but cannot verify.

What browsers does this problem apply to, if applicable?

Safari

What did you expect to see?

I expect the compat data to no longer show safari as supporting.

Did you test this? If so, how?

Yes, via data:text/html,<script>alert('MutationEvent' in window);</script>

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

WebKit/WebKit@909da23 - the PR that disabled mutation events within WebKit.

Do you have anything more you want to share?

No response

MDN URL

https://developer.mozilla.org/en-US/docs/Web/API/MutationEvent

MDN metadata

MDN page report details

• Query: api.MutationEvent
• Report started: 2025-08-19T16:17:42.924Z