We’re excited to share a major milestone with our partner community: Excel now supports Undo for 3rd-party web add-ins! This long-awaited capability unlocks a more seamless, professional experience for both developers and end users and addresses one of the top requests from our ISV ecosystem.

Excel Undo support: Empowering users with confidence and flexibility

The introduction of Undo support in the Excel Office.js API marks a significant improvement for users and developers alike. Previously, API calls performed by 3P web add-ins would clear the entire undo stack, which meant users could only manually revert to a previous status. With the latest release, most user action performed by your web add-in can now be undone using the familiar ribbon Undo button or keyboard shortcut (Ctrl+Z). The default unit of undo is each context.sync() call, making it easy to align undo behavior with user actions.

This update empowers users to work with greater confidence and creativity. Imagine a finance modeling add-in where professionals can accept automatic formula suggestions without hesitation—knowing that a simple Ctrl+Z will instantly revert any change.

Customizable Undo grouping for developers

We know that flexibility matters. While the default “one action, one undo” model works for most scenarios, some advanced workflows require more control. That’s why we’re introducing Undo Grouping:

• Group multiple actions into a single undo: Developers can use JavaScript closures to group several sync() calls, defining custom undo boundaries that match complex user workflows.
• Timeout and force-end mechanisms: To ensure reliability, undo groups have sensible defaults (20 seconds, max 120 seconds) and can be customized for special cases.

This approach minimizes developer effort while providing the flexibility needed for sophisticated add-in scenarios.

Get started today!

For implementation details, see Undo support with the Excel JavaScript API on Microsoft Learn.

Have feedback or need a specific API supported? File a request in our office-js GitHub issues page—your input shapes our roadmap!

Thank you for partnering with us to make Excel more powerful and user-friendly for everyone. We can’t wait to see what you build next!

— The Excel Chat and Office Extensibility (ECOE) team