How to Build an Excel (XLS/XLSX) Viewer in JavaScript

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Illustration: How to Build an Excel (XLS/XLSX) Viewer in JavaScript

In this blog post, learn how to build a JavaScript Excel viewer using the PSPDFKit for Web SDK. You’ll open and view XLS or XLSX files directly in your web browser using client-side processing (no server required).

The image below shows what you’ll be building.

resulting image

You can check out the demo to see it in action.

Opening and Rendering Office Documents in the Browser

PSPDFKit for Web brings support for Word, Excel, and PowerPoint formats to your application, without you or your users needing any MS Office software, MS Office licenses, or third-party open source software. The technology works by converting an Office document to PDF directly in the browser, and the document is then rendered in our JavaScript viewer.

For both manual and npm installations, it’s important to note that the assets must be copied to a public folder. Make sure your server has the Content-Type: application/wasm MIME typeset, as explained in our troubleshooting guide.

To serve the files, you need to use an npm package like serve as a simple HTTP server.

Unlocking More Capabilities with Office-to-PDF Conversion

By using Office-to-PDF conversion, you have the option to support a rich array of additional Office document functionality, such as:

Text editing — Edit text directly in the displayed Office document.
Page manipulation — Organize documents by adding, removing, or rearranging pages.
Annotations — Boost collaboration by adding text highlights, comments, or stamps.
Adding signatures — Draw, type, or upload a signature directly to an Excel document.

Explore Demo

Requirements to Get Started

To get started, you’ll need:

The latest stable version of Node.js.
A package manager compatible with npm. This guide contains usage examples for the npm client (installed with Node.js by default).

Adding PSPDFKit to Your Project

Install the pspdfkit package from npm. If you prefer, you can also download PSPDFKit for Web manually:

npm install pspdfkit

For PSPDFKit for Web to work, it’s necessary to copy the directory containing all the required library files (artifacts) to the assets folder. Use the following command to do this:

cp -R ./node_modules/pspdfkit/dist/ ./assets/

Make sure your assets directory contains the pspdfkit.js file and a pspdfkit-lib directory with the library assets.

Integrating into Your Project

Add an Excel (XLS, XLSX) document you want to display to your project’s directory. You can use our demo document as an example.
Add an empty <div> element with a defined width and height to where PSPDFKit will be mounted:

<div id="pspdfkit" style="width:100%; height: 100vh;"></div>

Include pspdfkit.js in your HTML page:

<script src="assets/pspdfkit.js"></script>

Initialize PSPDFKit for Web in JavaScript by calling the load() method.

This method takes a configuration object as its parameter. The configuration object specifies the location of the document on the page, the path to the source document, and the optional license key:

<script>
	PSPDFKit.load({
		container: "#pspdfkit",
	 	document: "chart.xlsx" // Add the path to your document here.
	 	licenseKey: "YOUR_LICENSE_KEY" // Remove this line if you're using the free trial.
	})
</script>

This code will load chart.xlsx into the element with the ID pspdfkit.

You can see the full index.html file below:

<!DOCTYPE html>
<html>
	<head>
		<title>My App</title>
		<!-- Provide proper viewport information so that the layout works on mobile devices. -->
		<meta
			name="viewport"
			content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"
		/>
	</head>
	<body>
		<!-- Element where PSPDFKit will be mounted. -->
		<div id="pspdfkit" style="width:100%; height: 100vh"></div>

		<script src="assets/pspdfkit.js"></script>
		<script>
			PSPDFKit.load({
				container: '#pspdfkit',
				document: 'chart.xlsx', // Add the path to your document here.
			})
				.then(function (instance) {
					console.log('PSPDFKit loaded', instance);
				})
				.catch(function (error) {
					console.error(error.message);
				});
		</script>
	</body>
</html>

Serving Your Website

You’ll use the npm serve package to serve your project.

Install the serve package:

npm install --global serve

Serve the contents of the current directory:

serve -l 8080 .

Navigate to http://localhost:8080 to view the website.

A Note about Fonts

When you convert an Office document with custom fonts to a PDF, PSPDFKit for Web might not have access to these fonts due to licensing constraints. In this case, PSPDFKit typically replaces unavailable fonts with their equivalents — like Arial with Noto.

Adding Even More Capabilities

Once you’ve deployed your viewer, you can start customizing it to meet your specific requirements or easily add more capabilities. To help you get started, here are some of our most popular JavaScript guides:

Conclusion

In this blog post, you learned how to build an Excel viewer using JavaScript with the PSPDFKit SDK. It also discussed the benefits of using PSPDFKit for Web Standalone to render Office documents in the browser. If you hit any snags, don’t hesitate to reach out to our Support team for help.

You can also integrate our JavaScript Excel viewer using web frameworks like Angular, Vue.js, and React.js. To see a list of all web frameworks, start your free trial. Or, launch our demo to see our viewer in action.

Author

Hulya Masharipov Technical Writer

Hulya is a frontend web developer and technical writer at Nutrient who enjoys creating responsive, scalable, and maintainable web experiences. She’s passionate about open source, web accessibility, cybersecurity privacy, and blockchain.

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