Microsoft Edge 126.0.2592.68 — Last version with support for Mutation Events

Version Microsoft Edge 126.0.2592.68 is the last version of Edge that allows enabling support for Mutation Events, a deprecated DOM feature that was widely used in older web applications. Like Chrome, Edge is based on Chromium, and this version is aligned with Chromium 126, which still includes the hidden flag to enable Mutation Events manually.

What are Mutation Events?

Mutation Events are legacy browser features that detect real-time DOM changes on a page. Examples include:

  • DOMNodeInserted
  • DOMNodeRemoved
  • DOMSubtreeModified

Although deprecated, some older systems and enterprise tools still rely on these events to function correctly.

From version 127 onward, Chromium has removed support completely, and so has Microsoft Edge.

Why use Edge 126.0.2592.68?

This version lets you:

  • Run legacy enterprise or educational platforms that depend on deprecated DOM events
  • Avoid the "MutationEvent is not defined" error
  • Temporarily restore compatibility with tools that have not migrated to MutationObserver

Note: Mutation Events have been deprecated for security and performance reasons. Use only when strictly necessary.

How to enable Mutation Events in Edge

  1. Launch Edge 126.0.2592.68
  2. Navigate to the experimental flags: edge://flags
  3. In the search box, enter: mutation
  4. Locate the flag: Enable (Deprecated) synchronous mutation events
  5. Change it to: Enabled
  6. Click Restart to apply the setting

Where to download Edge 126.0.2592.68?

You can download it here:

👉 Download Microsoft Edge 126.0.2592.68 (Windows 64-bit)

Make sure to select version 126 manually if it has already been superseded by version 127 or newer.

⚠️ This version will not receive future security updates. Use only in isolated or testing environments.

⚠️ Final Note

As of version 127, Microsoft Edge no longer includes any option to re-enable Mutation Events — even via hidden flags.
This makes Edge 126.0.2592.68 your last chance to run older systems that still depend on this obsolete feature.