Learn about changes coming to Office Add-in user experiences.

Laptop on a desk displaying an Excel spreadsheet with a task pane Excel add-in

Build powerful applications for Excel

Extend Excel functionality and access Excel data over the web.

Extend Excel functionality with Office Add-ins

With the Office Add-ins platform, you can extend Excel's functionality through a web app that runs within the Excel client on multiple platforms such as Windows, Online, Mac OS, iPad. Unlike COM and VSTO add-ins, Office Add-ins can do almost anything a webpage can do inside a browser. This technology is enabled using the JavaScript API for Office known as Office.js.

Access Excel data with Microsoft Graph

Use the Excel REST API in Microsoft Graph to extend the value of your Excel data, calculations, reporting, and dashboards. With Microsoft Graph, you can read and modify Excel workbooks that are stored in OneDrive, SharePoint, or other supported storage platforms. By issuing REST API requests to Microsoft Graph, your web or mobile application can access Excel objects.

What can I do with Excel?

Extend Excel functionality with Office web add-ins

Record, edit, and create Office Scripts to automate tasks

Add your own custom functions

Work with Microsoft Graph data

Excel developer resources

Code

Community calls

Documentation

Blogs

Microsoft Q&A forum

Add-ins community

What's new in Excel development

Ignite 2025 - What's new for Office Add-ins

Excel announces undo support for 3rd-party web add-ins

Dynamic DPI code samples

Analyze Excel data with charts