Top JavaScript PDF Viewer SDKs and Choosing One That’s Right for You

By Garry Klooesterman | 2026 Jan 02

7 min

Introduction

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As technology constantly evolves, PDFs become more and more complex. They aren’t just digital replacements of paper documents anymore. They are full of data, forms, signatures, and more. For developers, the goal is to find a solution that handles all the business demands and requirements without slowing down your app. Accessibility and security are also important factors to keep in mind. For accessibility, the viewer has to work for users of all abilities. In terms of security, not having to rely on outside dependencies is key to keeping your data safe.

Whether you're building a simple PDF viewer or an app with digital signature and annotation features, the engine you choose matters.

In this blog, we’ll look at some of the top JavaScript PDF viewer SDKs, like the Apryse WebViewer SDK and PDF.js. We’ll also cover features, considerations, and frequently asked questions.

What is a JavaScript PDF Viewer?

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In its simplest form, a JavaScript PDF viewer lets you open and use PDF files directly in a web browser. These SDKs take the PDF data and turn it into something a browser can show, so you can control the experience without needing extra plugins.

Top JavaScript PDF Viewer SDKs

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Here is a breakdown of the top choices for JavaScript PDF viewer SDKs.

PDF.js

PDF.js is made for basic viewing when you have budget restrictions. It’s a free, open-source option that supports plain JavaScript. Developed by Mozilla, this is the engine that powers the PDF viewer inside Firefox. It is the most widely used library and is the foundation for almost every free SDK out there.

Features: It provides the core elements to render a PDF into HTML5 Canvas or SVG. It supports text searching and basic page navigation.
Benefits: It is 100% free and open source. Because it’s backed by Mozilla, it is highly stable and frequently updated to handle the latest web standards.
Challenges: It is a rendering engine, not a viewer. It has no UI out of the box, so you won't find a Save button, a Zoom slider, or a Print icon. You have to build the entire UI yourself, which can lead to many hours of development time for a production-ready app.
Hurdles: It struggles with complex PDF elements such as shading, gradients, and transparency, and lacks support for advanced features like form-filling or digital signatures.
Security: Since it is open source, bugs are found and fixed quickly. However, you have to be careful with documents that might have bad code hidden in them.

Ngx-extended-pdf-viewer

Ngx-extended-pdf-viewer is good for Angular projects that need more than just the basic features. It’s an open-source option that is the most complete free option. It adds a lot of the features that are missing from the basic PDF.js library.

Features: It includes a full-featured toolbar, sidebar thumbnails, printing, and a multi-language UI right out of the box. It also adds a unique form-filling layer.
Benefits: It saves build time with a pre-built UI that feels integrated into the Angular lifecycle. It’s also configurable using HTML attributes.
Challenges: It is strictly coupled to Angular. If you move to React or a different framework, you have to start over. It also has the same rendering limitations as PDF.js, as PDF.js is the main engine for this SDK.
Hurdles: Maintaining version compatibility between this SDK and your version of Angular can occasionally be tricky as the project evolves.
Security: It uses Angular's security features, but it still relies on the basic PDF.js engine. It doesn't have advanced tools for things like secure redaction.

React-PDF

React-PDF is ideal for React developers who need a simple way to show documents. It’s another free, open-source option that’s a very popular choice for those already using React as it wraps PDF.js into components that feel natural for a React dev. React-PDF allows you to treat a PDF page as a standard React component.

Features: It allows you to render specific pages of a PDF within your component tree for scrolling views or apps where you want to overlay your own custom React buttons on top of a document.
Benefits: It feels natural to React developers. React-PDF is easy to fit into your code and gives you a lot of control over where the document sits on the page.
Challenges: You have to build the UI functions like zoom and search yourself.
Hurdles: Performance can be greatly affected if you try to render too many pages at once in a large list as the browser's memory management for the Canvas elements can become a bottleneck.
Security: Since it uses PDF.js, it has the same security setup. Just be mindful of the documents you’re using and the potential of hidden code in them.

Pdfvuer

Pdfvuer is a strong choice for Vue.js developers who want a quick, component-style viewer. It’s a free, open-source option that is a solid middle ground for Vue developers. Similar to React-PDF, Pdfvuer is a wrapper for the Vue framework. It’s designed to make the integration of PDF.js feel native to a Vue application’s data flow.

Features: It provides a component-based approach to rendering, allowing for easy integration with Vue’s Single File Components (SFCs).
Benefits: It supports both Vue 2 and Vue 3. It’s also easy to get a basic document showing on a page.
Challenges: The community is smaller, so there aren't as many updates or guides as there are for React or Angular.
Hurdles: Because it is maintained by a smaller group of contributors, security patches and bug fixes may take longer to roll out.
Security: Its security is only as good as the version of PDF.js it is using, so it may not be the right choice when dealing with highly sensitive data.

Apryse WebViewer SDK

Apryse WebViewer SDK is best for professional apps that need editing, signing, and top-tier security. It’s a commercial option that works with many frameworks, such as React, Vue, and Angular. It’s built for apps where more complex capabilities are needed.

Apryse WebViewer SDK doesn’t rely on the browser’s native rendering or the open-source PDF.js engine. It uses its own proprietary engine to provide a consistent, high-performance experience across all browsers.

Features: It is the only SDK on this list that handles MS Office (Word, Excel, PPT) and CAD drawings directly in the browser without server-side conversion. It includes over 35 annotation tools, real-time collaboration, and a full-fledged e-signature workflow.
Benefits: Apryse provides true redaction, so rather than just placing a black box over text, which can still be scraped from the underlying file, the SDK permanently deletes the data. It also includes an open-source UI on GitHub, meaning you can customize every button and theme to match your branding perfectly.
Challenges: As a commercial product, it does require a license. It is also a larger library because of the expanded feature set, but its modular loading system helps reduce initial load times.
Security: This is the strongest point for Apryse. Everything happens on the user's device without the need for external dependencies, so your data stays private.

For more information, see our Document SDK Buyer’s Guide.

Get Started: Check out the Apryse WebViewer SDK free trial.

How to Choose the Right JS PDF Viewer SDK

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Choosing the right SDK ultimately depends on the needs and requirements of your business and users. You need to consider the options that your users will need. For example, do they just need to view documents, or do they also need to sign or edit them? Also, how big are the files they’ll be working with?

Here are some key points for choosing an SDK.

Rendering Quality

If a document doesn't look exactly like it’s supposed to, your users will lose trust in your app. High-quality rendering is about font accuracy, image placement, and layout integrity. If you're handling complex legal contracts or blueprints, even a slight shift in formatting can be a disaster. You want an engine that produces sharp, clear text and keeps the document’s original visual integrity intact.

Security

When it comes to security, you need to know what the vendor is using to build their SDK. Is the code proprietary or is it just a fork of an old open-source project? If it's a fork, you could be inheriting the library’s vulnerabilities. Also, you need to consider where the processing happens. If an SDK forces you to send files to a third-party server for processing, that can be a serious concern for data privacy. The safest bet is always client-side processing where the data never leaves the user's machine.

Scalability

Switching SDKs can be a nightmare. It’s expensive, time-consuming, and delays your projects. When you pick a tool today, you’re also picking it for what you’ll need in the future. Open-source tools are rarely built to handle high-volume, enterprise-scale production. By choosing a robust, feature-rich SDK from the start, you avoid the vendor gap where you suddenly have to add a second tool for a feature your first tool doesn't have.

Support

Your ROI depends on how fast your team can get a Proof of Concept (POC) running. If the documentation is lacking or difficult to follow and there’s no code samples, your developers will waste precious time trying to get a button to work. Look for helpful resources like guides, blogs, video tutorials, and active sample apps. Also, check out the support to see how quickly you’ll get an expert who can help resolve your issue.

Stability and Performance

Performance matters in multiple ways, from how fast a page loads to how responsive the UI feels. If the UI is laggy, unintuitive, or crashes on large files, users will likely stop using it and go back to their old, inefficient workflows. You need an SDK that stays stable under increased demands, providing a smooth UX that doesn't make the user wait or wonder if the app has frozen.

FAQ

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Are free PDF viewer SDKs good enough for a business app?

While free libraries are great for simple viewing, they often lack more complex features users also need such as e-signatures, MS Office support, or secure redaction. Apryse provides these out of the box with a customizable UI, so your team can focus on more important things instead of reinventing the wheel for document viewing.

Can I customize the UI of JavaScript PDF viewers?

Yes. Most JavaScript PDF viewers allow you to configure the UI to some degree. Others like the Apryse WebViewer SDK offer complete control over functionality, behavior, and appearance.

Does Apryse offer a free trial?

Yes. You can use the free trial to build your app, and you can see if it works for your project before you ever have to pay for a license.

Can I host my own files?

Yes. All of these let you load PDFs from your own server or cloud storage like AWS.

Which is the easiest option to set up?

If you’re looking for a JavaScript PDF viewer SDK that can do more than just display a PDF, the Apryse WebViewer SDK has the enhanced capabilities you need and is the easiest to integrate into your projects.

Conclusion

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The right SDK really depends on the needs of your business and users, but it also depends on how much time you have and your expertise. If you have the time and skills to build your own UI and functions, open-source options such as PDF.js and React-PDF are a good way to save money.

However, that savings comes at a price. With less support available, these options run the risk of being affected by bugs over time. For real and critical use cases, the Apryse WebViewer SDK is the better and safer option. It gives you a professional, secure viewer that just works out of the box, so you can focus on building the rest of your app.

Try the Apryse WebViewer SDK with a free trial or check out the documentation.

Contact our sales team for any questions or jump on Discord for support and discussions.