Build an Excel task pane add-in

In this article, you'll walk through the process of building an Excel task pane add-in.

Create the add-in

You can create an Office Add-in by using Visual Studio or any other editor. Tell us what editor you'd like to use by choosing one of the following tabs:


Create the add-in project

  1. On the Visual Studio menu bar, choose File > New > Project.

  2. In the list of project types under Visual C# or Visual Basic, expand Office/SharePoint, choose Add-ins, and then choose Excel Web Add-in as the project type.

  3. Name the project, and then choose OK.

  4. In the Create Office Add-in dialog window, choose Add new functionalities to Excel, and then choose Finish to create the project.

  5. 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 manifest file, which contains all the settings that describe your add-in. These settings help the Office host 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. You 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 code

  1. Home.html specifies the HTML that will be rendered in the add-in's task pane. In Home.html, replace the <body> element with the following markup and save the file.

    <body class="ms-font-m ms-welcome">
        <div id="content-header">
            <div class="padding">
        <div id="content-main">
            <div class="padding">
                <p>Choose the button below to set the color of the selected range to green.</p>
                <br />
                <h3>Try it out</h3>
                <button class="ms-Button" id="set-color">Set color</button>
  2. Open the file Home.js in the root of the web application project. This file specifies the script for the add-in. Replace the entire contents with the following code and save the file.

    'use strict';
    (function () {
        Office.onReady(function() {
            // Office is ready
            $(document).ready(function () {
                // The document is ready
        function setColor() {
   (context) {
                var range = context.workbook.getSelectedRange();
                range.format.fill.color = 'green';
                return context.sync();
            }).catch(function (error) {
                console.log("Error: " + error);
                if (error instanceof OfficeExtension.Error) {
                    console.log("Debug info: " + JSON.stringify(error.debugInfo));
  3. Open the file Home.css in the root of the web application project. This file specifies the custom styles for the add-in. Replace the entire contents with the following code and save the file.

    #content-header {
        background: #2a8dd4;
        color: #fff;
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 80px; 
        overflow: hidden;
    #content-main {
        background: #fff;
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        bottom: 0;
        overflow: auto; 
    .padding {
        padding: 15px;

Update the manifest

  1. Open the XML manifest file in the add-in project. This file defines the add-in's settings and capabilities.

  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 task pane add-in for Excel.

  5. Save the file.

    <ProviderName>John Doe</ProviderName>
    <!-- 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 task pane 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 Show Taskpane add-in button displayed in the ribbon. The add-in will be hosted locally on IIS.

  2. In Excel, choose the Home tab, and then choose the Show Taskpane button in the ribbon to open the add-in task pane.

    Excel add-in button

  3. Select any range of cells in the worksheet.

  4. In the task pane, choose the Set color button to set the color of the selected range to green.

    Excel add-in

Next steps

Congratulations, you've successfully created an Excel task pane add-in! Next, learn more about the capabilities of an Excel add-in and build a more complex add-in by following along with the Excel add-in tutorial.

See also