Firefox Browser Add-ons
  • Extensions
  • Themes
    • for Firefox
    • Dictionaries & Language Packs
    • Other Browser Sites
    • Add-ons for Android
Log in
Preview of Mutation Events Polyfill

Mutation Events Polyfill by Norvyll

Polyfills deprecated Mutation Events (DOMNodeInserted, DOMSubtreeModified, etc.) using MutationObserver, ensuring compatibility for sites that rely on these events after their removal in Chrome 127+ and future Firefox versions.

Available on Firefox for Android™Available on Firefox for Android™
0 (0 reviews)0 (0 reviews)
Download Firefox and get the extension
Download file

Extension Metadata

About this extension
Automatically injects a MutationObserver-based polyfill on every page to restore support for deprecated Mutation Events. Useful for sites and legacy scripts relying on DOMNodeInserted, DOMNodeRemoved, DOMSubtreeModified, and related events.
Rated 0 by 0 reviewers
Sign in to rate this extension
There are no ratings yet

Star rating saved

5
0
4
0
3
0
2
0
1
0
No reviews yet
Permissions and data

Required permissions:

  • Access your data for all websites

Data collection:

  • The developer says this extension doesn't require data collection.
Learn more
More information
Add-on Links
  • Support Email
  • Copy add-on ID
Version
1.0.8
Size
9.99 KB
Last updated
18 days ago (May 27, 2026)
Related Categories
  • Web Development
License
BSD-3-Clause
Version History
  • See all versions
Add to collection
Report this add-on
Go to Mozilla’s homepage

Add-ons

  • About
  • Firefox Add-ons Blog
  • Extension Workshop
  • Developer Hub
  • Developer Policies
  • Community Blog
  • Forum
  • Report a bug
  • Review Guide

Browsers

  • Desktop
  • Mobile
  • Enterprise

Products

  • Browsers
  • VPN
  • Relay
  • Monitor
  • Pocket
  • Bluesky (@firefox.com)
  • Instagram (Firefox)
  • YouTube (firefoxchannel)
  • Privacy
  • Cookies
  • Legal

Except where otherwise noted, content on this site is licensed under the Creative Commons Attribution Share-Alike License v3.0 or any later version. Android is a trademark of Google LLC.