The six best JavaScript PDF viewers

This post covers:

• What a JavaScript PDF viewer is

• Common use cases

• Key factors for selecting the right viewer

• Cost considerations — Open source vs. commercial options

• A rundown of the top JavaScript PDF viewers, including Nutrient Web SDK and others like PDF.js, react-pdf, ngx-extended-pdf-viewer, pdfvuer, and Apryse WebViewer

• Tips for optimizing performance with large files and ensuring security

What is a JavaScript PDF viewer?

A JavaScript PDF viewer uses JavaScript to render PDF documents for display inside a web browser. The viewer can be embedded inside a webpage or in a JavaScript-based application to directly display PDF documents. JavaScript PDF viewers run entirely client-side and don’t require a server component.

Beyond its PDF rendering capability, a PDF viewer will also include a user interface (UI) that enriches the user experience (UX) with capabilities such as zooming, page navigation, text search, and more.

A PDF viewer typically won’t include editing features that modify the underlying document. However, some PDF viewers have basic editing capabilities and can be extended or upgraded to include features such as annotation, form filling, signing, and page manipulation. If you plan to add editing capabilities in the future, it’s worth considering a PDF viewer that can be easily extended or upgraded without rewriting your code.

Common use cases for JavaScript PDF viewers

JavaScript PDF viewers do more than just display PDFs; they streamline workflows across various industries:

• Sharing documents — Embed PDFs directly into websites or apps for seamless access without downloads, enhancing user engagement.

• Financial and legal — Support collaborative workflows by displaying and annotating documents for reviews and approvals, keeping everyone updated with the latest version.

• Education — Facilitate sharing syllabi or assignments, enabling collaboration through in-document comments and edits synced across devices.

• Architecture and construction — Display blueprints, annotate changes, and measure directly in PDFs, even offline in remote locations.

• Document security — Protect sensitive content with restricted access, watermarks, and limited download or print options.

How to choose the right JavaScript PDF viewer

When selecting a JavaScript PDF viewer, consider these key factors:

• Security — Ensure the viewer is built on a secure PDF engine to protect against vulnerabilities.

  Nutrient is designed with security in mind, using an optimized fork of PDFium (the secure PDF engine used in Chromium) and undergoing independent third-party audits.

• Privacy — Verify that the library doesn’t collect or transmit user data. Nutrient, for instance, doesn’t gather any information about users or documents, ensuring complete privacy.

• UI customization — Look for flexible customization options, from basic theming to advanced API integrations.

  Nutrient offers robust customization tools, enabling seamless integration while protecting against UI-related vulnerabilities.

• Features — Ensure the viewer includes essential features like text search, zooming, navigation, and permissions.

  Nutrient also supports advanced features like annotations, form filling, signing, and real-time collaboration, making it a scalable choice for evolving needs.

Nutrient’s thorough documentation and reliable support make it easier to extend its functionality and ensure long-term usability.

What is the cost of a JavaScript PDF viewer?

The cost of a JavaScript PDF viewer depends on whether you choose an open source or commercial viewer.

Open source JavaScript PDF viewers

Open source JavaScript PDF viewers don’t have any direct licensing costs and are available under open source licenses.

There can be indirect costs associated with efforts spent customizing or adding specific features. Since open source PDF viewers don’t provide dedicated support, this can impact upfront engineering investment and overall turnaround time if you run into any issues, or if documentation isn’t available.

Maintenance costs can be unpredictable if you’ve implemented any customizations. When updating an open source library to a newer version, it’s important to carefully review and test to ensure the latest version doesn’t break any of your customizations.

Generally, open source JavaScript PDF viewers are secure, so there’s a relatively low risk of security vulnerabilities. However, we recommend reviewing the Common Vulnerabilities and Exposures (CVE) database before making a decision.

Commercial JavaScript PDF viewers

The cost for commercial JavaScript PDF viewers is typically based on a number of variables:

• Whether it’ll be used internally by employees as part of a line-of-business application or in a product that’s redistributed to customers.

• The number of users and documents.

• The stage of your organization (i.e. startup vs. established business).

There can also be indirect costs associated with a commercial library. It’s important to evaluate technical support and documentation to accurately assess the effort to integrate and customize.

Some commercial viewers are available as a perpetual license with optional maintenance, while others are subscription-based. For the most part, commercial viewers will avoid releasing updates that break existing customizations.

Not all commercial libraries are secure. We recommend reviewing the Common Vulnerabilities and Exposures (CVE) database before making a decision.

The six best JavaScript PDF viewers

This next section will provide an overview of the six best JavaScript PDF viewers.

Nutrient Web SDK

Since 2011, we at Nutrient have been working with the PDF specification and have developed one of the most comprehensive PDF SDKs available on the market. During that time, we’ve worked with many clients — including Disney, IBM, UBS, and Dropbox — to help them improve how their users work with PDF documents.

Nutrient Web SDK is our JavaScript PDF library — an SDK that offers PDF viewing, along with more than 30 other document processing tools (with many more tools planned). Try our web demo to see what it can do.

Example of our JavaScript PDF viewer

To demo our JavaScript PDF viewer, upload a PDF, JPG, PNG, or TIFF file by clicking Open Document under the Standalone option (if you don’t see this option, select Choose Example from the dropdown). Once your document is displayed in the viewer, try drawing freehand, adding a note, or applying a crop or an eSignature.

Pros

• Enterprise-grade security — Built with robust security features, ensuring safe document handling and user privacy.

• Customizable UI — Offers deep customization options, including toolbar configuration, theme adjustments, and accessibility features.

• Responsive design — The viewer automatically adapts to different screen sizes, providing a seamless experience across devices.

• Assistive technology support — Includes features like keyboard shortcuts and screen reader support for improved accessibility.

• Extensibility — Easily extend the viewer with additional tools like annotation, form filling, signing, and real-time collaboration.

In addition to high-fidelity PDF rendering, one of the key benefits of Nutrient Web SDK is that you can easily extend your PDF viewer with additional document processing tools:

• Annotation

• Creating and filling forms

• Signing

• Page manipulation

• Real-time collaboration

• Conversion

Supported file types

• PDF and PDF/A

• Word, Excel, PowerPoint

• TIFF (multipage), JPG, and PNG

Cons

• Commercial license — Requires a paid license for most use cases, although a free trial is available.

Use cases

• Enterprise applications — Nutrient is well-suited for large-scale, enterprise-level applications, especially for industries needing high-security standards.

• Collaboration platforms — If your app requires real-time collaboration, Nutrient can seamlessly handle annotations, form filling, and document sharing.

Pricing

Nutrient has simple and flexible pricing that’s based on a couple factors: the number of components and products you require, and the total number of users accessing the technology. Unlike other commercial libraries, we don’t install invasive trackers in your application, and we never send any information about your documents or users to external servers.

You can learn more about the pricing on our website. If you want to test it out, you can get started with a free trial.

How to get started with Nutrient Web SDK

1. Create a project directory

Run the following in your terminal:

mkdir my-pdf-viewer && cd my-pdf-viewer

2. Initialize your project

Set up a Node.js project:

npm init -y

3. Install Nutrient

Install pspdfkit from npm:

npm install pspdfkit

4. Set up assets

Copy library files into an assets folder:

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

5. Add a PDF document

Place your PDF in the project directory, e.g. document.pdf. You can use our demo document as an example.

6. Create the HTML viewer

Create an index.html file with the following content:

<!DOCTYPE html>
<html>
	<head>
		<title>My PDF Viewer</title>
		<meta
			name="viewport"
			content="width=device-width, initial-scale=1.0"
		/>
	</head>
	<body>
		<div id="pspdfkit" style="height: 100vh;"></div>
		<script src="assets/pspdfkit.js"></script>
		<script>
			PSPDFKit.load({
				container: '#pspdfkit',
				document: 'document.pdf',
			})
				.then((instance) => {
					console.log('PSPDFKit loaded', instance);
				})
				.catch((error) => {
					console.error(error.message);
				});
		</script>
	</body>
</html>

7. Serve your project

Install and run the serve package:

npm install --global serve
serve -l 8080 .

Visit http://localhost:8080 to view your PDF viewer.

If you prefer a video tutorial, you can watch our step-by-step guide.

Additional resources

For more details, check out our guides, code samples, and API documentation.

If you’re looking for related tutorials, you might find these posts helpful:

• How to embed a PDF viewer in your website

• Convert HTML to PDF in JavaScript

These resources will give you actionable insights for working with Nutrient in your projects.

PDF.js

PDF.js is a popular open source JavaScript library launched by Mozilla in 2011 and maintained by a community of more than 360 contributors. It has more than 42K GitHub stars and is used by Firefox to open PDFs natively in the browser.

• It has a good security track record, with Mozilla quickly patching vulnerabilities (learn more in the security advisories).

• PDF.js doesn’t collect or transmit any information about users or documents.

• The UI is customizable through CSS theming and the API.

• Editing features are limited to ink and text annotations.

• Supports form filling for both XFA and AcroForms.

Supported file types

• PDF

Pricing

PDF.js is free and open source, available under the Apache License 2.0.

Pros

• Open source — Free to use, with a strong community supporting it.

• Wide adoption — Widely used, especially in Firefox and other browsers.

• Customizable UI — Allows adjustments to match your app’s branding and user experience.

Cons

• Basic features — Limited to annotations and lacks advanced editing features.

• Rendering performance — May struggle with large or complex PDFs, especially on lower-end devices.

Use cases

• Basic PDF viewing — Ideal for apps that only need to display PDFs.

• Browsers and websites — Supported natively by Firefox, making it perfect for browser-based applications.

If you’d like to get started with PDF.js, here are some helpful tutorials to get you up and running:

• Complete guide to PDF.js: The leading JavaScript library for PDF rendering
• How to build a JavaScript PDF viewer with PDF.js
• How to build a React PDF viewer with PDF.js
• How to build a TypeScript PDF viewer with PDF.js
• How to build a Vue.js PDF viewer with PDF.js
• How to build an Angular PDF viewer with PDF.js
• How to build an Electron PDF viewer with PDF.js

react-pdf

react-pdf is a popular open source React component that renders PDF files using PDF.js. It’s maintained by an open source community with 53 contributors and has more than 7K GitHub stars.

• It leverages PDF.js for rendering, ensuring compatibility and performance.

• There were no known vulnerabilities when this blog was published. Any vulnerabilities in PDF.js will also affect react-pdf.

• It doesn’t collect or transmit any information about users or documents.

• The UI is minimal and requires further customization through APIs to meet your needs.

• The same features as PDF.js, such as annotations and form filling, are available in react-pdf.

Supported file types

• PDF

Pricing

react-pdf is free and open source, available under the MIT license.

Pros

• React component — Specifically designed for React, making it easy to integrate.

• Uses PDF.js — Leverages PDF.js for rendering, ensuring compatibility.

• Flexible API — Provides an easy-to-use API for rendering individual pages and customizing the viewer.

Cons

• Basic UI — Requires further development for a more sophisticated interface.

• Performance on large documents — May experience performance issues with large or complex PDFs.

Use cases

• React projects — Ideal for React applications that need PDF display functionality.

• Single-page PDF viewing — Useful for apps displaying one PDF page at a time, such as documentation viewers.

Integration example

import { Document, Page } from 'react-pdf';

function MyPDFViewer() {
	return (
		<div>
			<Document file="/path/to/your/document.pdf">
				<Page pageNumber={1} />
			</Document>
		</div>
	);
}

When it’s crucial

• React-based apps — When building a React app and needing seamless PDF rendering.

• Single-page PDF display — Ideal for apps where only one PDF page is displayed at a time.

If you’d like to get started with react-pdf, here’s a helpful tutorial to get you up and running:

• How to build a React.js PDF viewer with react-pdf

ngx-extended-pdf-viewer

ngx-extended-pdf-viewer is a popular open source Angular component that wraps PDF.js to enable seamless PDF viewing. Maintained by a community of 26 contributors, it has garnered more than 350 GitHub stars.

• At the time of publishing, no vulnerabilities were known. However, since it uses PDF.js under the hood, any vulnerabilities in PDF.js will also affect ngx-extended-pdf-viewer.

• It doesn’t collect or transmit any user or document data.

• The UI is similar to PDF.js and customizable via CSS theming and API configuration. The documentation provides wizards to customize buttons, toolbars, sidebars, and thumbnails.

• Along with the features of PDF.js, it includes additional functionality such as prerendering, touch gestures, and events for an improved user experience.

Supported file types

• PDF

Pricing

ngx-extended-pdf-viewer is free and open source, available under the Apache License 2.0.

Pros

• Angular integration — Designed specifically for Angular, making it easy to use in Angular applications.

• PDF.js backend — Utilizes PDF.js for reliable rendering and compatibility.

• Enhanced features — Offers additional capabilities like touch gestures, prerendering, and event handling.

Cons

• Framework-specific — Limited to Angular projects, which restricts its use in other frameworks.

• Missing advanced tools — Lacks features like form filling and real-time collaboration.

Use cases

• Angular applications — Ideal for Angular-based apps requiring robust PDF viewing.

• Touchscreen support — Great for mobile and tablet apps with touch gesture and zooming functionality.

Integration example

<ngx-extended-pdf-viewer
	[src]="'/path/to/document.pdf'"
	[textLayer]="true"
	[showHandToolButton]="true"
	[showPresentationModeButton]="true"
	[showDownloadButton]="true"
></ngx-extended-pdf-viewer>

When it’s crucial

• Angular projects — Essential for Angular apps that require PDF viewing capabilities.

• Mobile and tablet optimization — Perfect for applications targeting touch-based devices.

If you’d like to get started with ngx-extended-pdf-viewer, here’s a helpful tutorial to get you up and running:

• How to build an Angular PDF viewer with PDF.js

pdfvuer

pdfvuer is an open source Vue.js component that uses PDF.js for rendering PDF files. It has 19 contributors and more than 800 GitHub stars, and it’s available under the MIT license.

• No vulnerabilities were known at time of publishing, but it inherits any PDF.js issues.

• It doesn’t collect or transmit user or document data.

• Offers a basic UI, requiring customization via APIs.

• Provides the same features as PDF.js.

Supported file types

• PDF

Pros

• Vue.js integration — Easy to use in Vue.js applications.

• Lightweight — Minimal, efficient PDF viewer.

Cons

• Basic UI — Requires additional customization.

• Limited features — No form filling or annotations.

Use cases

• Vue.js projects — Lightweight PDF viewer for Vue-based apps.

• Simple PDF display — Ideal for displaying PDFs without advanced features.

Integration example

<pdfvuer :src="'/path/to/your/document.pdf'" />

If you’d like to get started with pdfvuer, here’s a helpful tutorial to get you up and running:

• How to build a Vue.js PDF viewer with PDF.js

Apryse JavaScript WebViewer

Apryse WebViewer is a commercially licensed library offering advanced PDF viewing and editing features.

• Security — Known for nine high-severity CVE vulnerabilities at the time of publishing, including issues in its UI.

• Data handling — Tracks document views and transmits data to third-party servers.

• Customizable UI — Open source UI, customizable via CSS and APIs.

• Features — Includes annotation, form filling and creation, signing, page manipulation, and conversion.

Supported file types

• PDF and PDF/A (excluding PDF/A 4)

• Word, Excel, PowerPoint

• TIFF, JPG, PNG, JFIF

Pricing

Apryse WebViewer is a commercial product with custom pricing provided by its sales team.

Pros

• Comprehensive features — Advanced tools for annotations, forms, and document signing.

• Wide format support — Handles multiple file types beyond PDF.

• Enterprise-ready — Designed for large-scale, enterprise use.

Cons

• Expensive — Pricing may be prohibitive for small projects.

• Privacy issues — Sends data to third-party servers, raising concerns.

Use cases

• Enterprise applications — Ideal for organizations requiring robust document tools and multi-format support.

• Advanced editing — Great for apps needing annotations, signing, and form management.

Comparison table

Here’s a side-by-side feature comparison table highlighting the key attributes of the six PDF viewers mentioned in this article.

This table will help you identify the best option based on specific project needs, such as integration ease, available features, support options, performance, and the ideal use case.

Summary of recommendations

• Best for small teams:

  • PDF.js, React PDF, and pdfvuer — All are free, easy to set up, and great for small teams needing a simple PDF viewer with basic features.

• Ideal for enterprise-grade projects:

  • Nutrient Web SDK and Apryse WebViewer — Both offer enterprise-level features like form filling, annotations, and real-time collaboration, making them perfect for large, secure, or collaborative applications.

• Best for lightweight apps:

  • PDF.js, React PDF, and pdfvuer — These options are suitable for lightweight applications where PDF viewing is the only requirement, with minimal setup and no need for advanced features.

• Best for document collaboration:

  • Nutrient Web SDK, Apryse WebViewer, and ngx-extended-pdf-viewer — These libraries support annotation, form filling, and collaboration, making them ideal for apps that involve teamwork or document editing.

How to optimize JavaScript PDF viewers for large files

Rendering large PDF files efficiently in JavaScript-based viewers can be challenging, especially for applications that require smooth user interactions.

The following sections explain how you can optimize JavaScript PDF viewers for large files.

1. Lazy loading pages

Load and render only the pages visible to the user instead of the entire document.

• Example — With PDF.js, use the getPage method to fetch pages dynamically as users scroll:

// Load the PDF.
const loadingTask = pdfjsLib.getDocument('path/to/your/large-pdf.pdf');
loadingTask.promise.then(function (pdf) {
	const totalPages = pdf.numPages;

	// Function to render a page.
	const renderPage = async (pageNumber) => {
		const page = await pdf.getPage(pageNumber);
		const viewport = page.getViewport({ scale: 1 });
		const canvas = document.createElement('canvas');
		const context = canvas.getContext('2d');
		canvas.height = viewport.height;
		canvas.width = viewport.width;

		const container = document.getElementById('pdf-container');
		container.appendChild(canvas);

		// Render the page
		page
			.render({ canvasContext: context, viewport })
			.promise.then(() => {
				console.log(`Page ${pageNumber} rendered`);
			});
	};

	// Example: Render the first page.
	renderPage(1);
});

2. Use web workers for rendering

To prevent blocking the main UI thread and ensure smooth user interactions, offload the rendering process to a web worker. PDF.js has built-in support for this approach, allowing rendering tasks to run in the background.

Here’s how to set it up:

import { GlobalWorkerOptions } from 'https://cdn.jsdelivr.net/npm/[email protected]/build/pdf.min.mjs';

// Specify the URL of the web worker script.
GlobalWorkerOptions.workerSrc =
	'https://cdn.jsdelivr.net/npm/[email protected]/build/pdf.worker.min.mjs';

// Load the PDF document.
const loadingTask = pdfjsLib.getDocument('large-file.pdf');
loadingTask.promise.then((pdf) => {
	console.log(`PDF loaded with ${pdf.numPages} pages.`);
});

By using a web worker, the PDF rendering process runs separately from the main UI, allowing the page to remain responsive even when handling large or complex PDFs.

3. Implement page caching

Cache rendered pages in memory to avoid rerendering when users revisit them.

• Maintain a map of rendered pages and their corresponding DOM elements.

4. Optimize canvas rendering

• Use lower resolutions for non-visible pages or thumbnails.

• Scale up only when necessary for zooming or printing.

5. Stream PDFs instead of downloading entire files

Use partial content requests to fetch and display PDF data incrementally. This improves the perceived loading speed, especially for large files.

6. Profile and test

• Use browser developer tools to identify bottlenecks in rendering and memory usage.

• Test with various file sizes to ensure smooth performance across scenarios.

Ensuring security in JavaScript-based PDF viewing

When implementing PDF viewers in JavaScript, security must be a priority to protect sensitive data and users from potential threats. Below are some essential practices to ensure secure PDF viewing.

1. Sanitize user-uploaded PDFs

• Validate and sanitize uploaded PDF files on the server to prevent malicious content.

• Remove embedded scripts or unsupported features that could compromise security.

2. Restrict file access

• Use strict permissions to ensure only authorized users can access specific documents.

• Secure URLs with token-based authentication to prevent unauthorized access.

3. Enable encrypted communication

• Always serve PDF files over HTTPS to prevent data interception.

• Use encrypted storage for sensitive documents.

4. Disable dangerous features

• Limit or disable JavaScript execution embedded in PDFs to prevent execution of malicious code.

• Use libraries that support safe rendering modes, like Nutrient Web SDK.

5. Implement access control

• Use role-based access control (RBAC) to restrict user actions like viewing, editing, or downloading.

• Example:

PSPDFKit.load({
	document: 'secure-document.pdf',
	container: '#viewer',
	permissions: {
		view: true,
		annotate: false,
		print: false,
	},
}).then((instance) => {
	console.log('Secure viewer loaded');
});

6. Monitor for vulnerabilities

• Keep your PDF library up to date with the latest security patches.

• Regularly scan for vulnerabilities in third-party libraries.

7. Secure data in transit and at rest

• Encrypt data at rest using secure algorithms.

• Ensure viewer sessions have limited lifetimes to reduce exposure.

8. Educate users

• Inform users about potential risks, such as opening unknown files or sharing sensitive PDFs.

By implementing these measures, you can create a secure and efficient environment for handling and viewing PDFs in JavaScript applications.

Final words

The best JavaScript PDF viewer for you depends entirely on your project’s requirements. While you should never make compromises in terms of security and privacy, you can be flexible with other factors and features.

If you only need to view PDFs and you don’t think your needs will expand in the future, then it’s a good idea to go with the most affordable solution. However, if you have — or predict having — more complex workflows, then the feature list becomes the crucial factor when selecting the right viewer.

If you want to test Nutrient’s JavaScript PDF viewer, you can get started with a free trial or play around with our web demo.

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