Build an Excel content add-in

In this article, you'll walk through the process of building an Excel content add-in using Visual Studio.

Prerequisites

• Visual Studio 2019 or later with the Office/SharePoint development workload installed.

  Note

  If you've previously installed Visual Studio, use the Visual Studio Installer to ensure that the Office/SharePoint development workload is installed.

• Office connected to a Microsoft 365 subscription (including Office on the web).

Create the add-in project

1. In Visual Studio, choose Create a new project.

2. Using the search box, enter add-in. Choose Excel Web Add-in, then select Next.

3. Name your project ExcelWebAddIn1 and select Create.

4. In the Create Office Add-in dialog window, choose the Insert content into Excel spreadsheets add-in type, then choose Next.

5. Choose the Basic Add-in or Document Visualization Add-in add-in template, and then choose Finish to create the project.

6. Visual Studio creates a solution and its two projects appear in Solution Explorer. The Home.html file opens in Visual Studio.

Explore the Visual Studio solution

When you've completed the wizard, Visual Studio creates a solution that contains two projects.

Project	Description
Add-in project	Contains only an XML-formatted add-in only manifest file, which contains all the settings that describe your add-in. These settings help the Office application determine when your add-in should be activated and where the add-in should appear. Visual Studio generates the contents of this file for you so that you can run the project and use your add-in immediately. Change these settings any time by modifying the XML file.
Web application project	Contains the content pages of your add-in, including all the files and file references that you need to develop Office-aware HTML and JavaScript pages. While you develop your add-in, Visual Studio hosts the web application on your local IIS server. When you're ready to publish the add-in, you'll need to deploy this web application project to a web server.

Update the manifest

1. In Solution Explorer, go to the ExcelWebAddIn1 add-in project and open the ExcelWebAddIn1Manifest directory. This directory contains your manifest file, ExcelWebAddIn1.xml. The manifest file defines the add-in's settings and capabilities. See the preceding section Explore the Visual Studio solution for more information about the two projects created by your Visual Studio solution.

2. The ProviderName element has a placeholder value. Replace it with your name.

3. The DefaultValue attribute of the DisplayName element has a placeholder. Replace it with My Office Add-in.

4. The DefaultValue attribute of the Description element has a placeholder. Replace it with A content add-in for Excel..

5. Save the file. The updated lines should look like the following code sample.

   ...
   <ProviderName>John Doe</ProviderName>
   <DefaultLocale>en-US</DefaultLocale>
   <!-- The display name of your add-in. Used on the store and various places of the Office UI such as the add-ins dialog. -->
   <DisplayName DefaultValue="My Office Add-in" />
   <Description DefaultValue="A content add-in for Excel."/>
   ...
   

Try it out

1. Using Visual Studio, test the newly created Excel add-in by pressing F5 or choosing the Start button to launch Excel with the content add-in displayed in the spreadsheet.

2. Ensure that there's text in the worksheet, then select any range of cells containing text in the worksheet.

3. Select the tab for the template you chose, then follow the instructions.

   Basic Add-in

   • In the content add-in, choose the Get data from selection button to get the text from the selected range.

     

   Document Visualization Add-in

   • In the content add-in, choose the Insert sample data button to add sample data to the worksheet and display a visualization.

     

Note

To see the console.log output, you'll need a separate set of developer tools for a JavaScript console. To learn more about F12 tools and the Microsoft Edge DevTools, visit Debug add-ins using developer tools for Internet Explorer, Debug add-ins using developer tools for Edge Legacy, or Debug add-ins using developer tools in Microsoft Edge (Chromium-based).

Next steps

Congratulations, you've successfully created an Excel content add-in! Next, learn more about developing Office Add-ins with Visual Studio.

Troubleshooting

• Ensure your environment is ready for Office development by following the instructions in Set up your development environment.

• Some of the sample code uses ES6 JavaScript. This isn't compatible with older versions of Office that use the Trident (Internet Explorer 11) browser engine. For information on how to support those platforms in your add-in, see Support older Microsoft webviews and Office versions. If you don't already have a Microsoft 365 subscription to use for development, you might qualify for a Microsoft 365 E5 developer subscription through the Microsoft 365 Developer Program; for details, see the FAQ. Alternatively, you can sign up for a 1-month free trial or purchase a Microsoft 365 plan.

• If your add-in shows an error (for example, "This add-in could not be started. Close this dialog to ignore the problem or click "Restart" to try again.") when you press F5 or choose Debug > Start Debugging in Visual Studio, see Debug Office Add-ins in Visual Studio for other debugging options.

Code samples

• Excel Content Add-in Humongous Insurance

See also

• Office Add-ins platform overview
• Develop Office Add-ins
• Excel JavaScript object model in Office Add-ins
• Excel add-in code samples
• Excel JavaScript API reference
• Using Visual Studio Code to publish