Comparing open source PDF libraries (2025 edition)

Many developers rely heavily on libraries to manipulate and generate PDFs—especially in web and server environments. But the open source landscape for PDF handling is fragmented. Each library serves a slightly different purpose, with varying degrees of browser or Node.js support, form capabilities, and flexibility. In this article, we compare the most relevant libraries in 2025 and highlight which use cases they best serve.

Comparison Table: JavaScript PDF Libraries at a Glance

Before we dive into individual libraries, here’s a quick side-by-side look at how the top JavaScript PDF tools compare in terms of use case, support, and developer experience.

Library-by-Library Breakdown

Let’s take a closer look at each open source PDF library to better understand where it shines—and where it may fall short depending on your use case.

pdf-lib

pdf-lib is a modern PDF library that works in both Node.js and browser environments—without any native dependencies. Although official releases have slowed in recent years, it remains popular for tasks like form filling, PDF merging, and document manipulation thanks to its clean API and TypeScript support.

Pros:

• Runs in both browser and server environments

• Modern TypeScript support with tree-shakable modules

• Intuitive API for merging, splitting, and modifying PDFs

• No external dependencies

Cons:

• Limited native support for complex forms (e.g., conditional logic, live validation)

• No rendering capabilities—pairing with another library may be needed for full pipelines

Best for: Developers who need full PDF manipulation without relying on a heavyweight SDK or server-side processing engine.

jsPDF

First released around 2010, jsPDF was one of the earliest JavaScript libraries to enable PDF generation entirely in the browser. It became a pioneer in lightweight, client-side exports, and remains widely used today for basic PDF generation in apps that need simplicity and fast output.

Pros:

• Extremely easy to use with a low learning curve

• Active community and lots of code samples

• Plugin ecosystem for tables, images, and charts

Cons:

• Lacks robustness for multi-page, styled, or form-heavy documents

• Minimal form support and limited layout control

• Some rendering quirks on complex layouts

Best for: Developers creating lightweight PDFs quickly in the browser with minimal setup or infrastructure.

pdfmake

Built on top of the PDFKit engine and designed with a declarative JSON structure, pdfmake brings a unique approach to PDF creation. It enables developers to define document layouts and content in a structured, programmatic way—ideal for templated reports and data-driven document generation.

Pros:

• JSON-based document structure is easy to programmatically generate

• Built-in support for tables, styles, and multiple content types

• Can run in both browser and Node.js

Cons:

• Less intuitive than API-driven libraries like pdf-lib

• Larger bundle size in the browser

• Limited form interactivity

Best for: Teams building dynamic documents from structured data or server-side PDF generation using templating systems.

PDF.js

Maintained by Mozilla, PDF.js is an open source rendering engine that uses HTML5 and JavaScript to display PDF content natively in the browser. Originally developed to showcase what web standards could do, it has become the backbone of many PDF viewers and preview tools on the web.

Pros:

• Highly reliable rendering engine with broad PDF support

• Enables embedding PDFs into custom viewer interfaces

• Integrates well with browser-native technologies

Cons:

• Cannot generate or modify PDFs

• No built-in interactivity or form control

Best for: Applications that need to render PDFs directly in the browser, such as readers, preview tools, and annotation systems.

Developer Takeaways: When to Use What

Not every project has the same needs—and not every PDF library fits every scenario. Here’s a quick guide for choosing the right tool:

• Use pdf-lib if you need a modern, all-purpose PDF creation and manipulation library that works both in Node and the browser.

• Use jsPDF if you want the quickest way to export a basic PDF in the browser with minimal configuration.

• Use pdfmake if your documents are data-driven and you prefer defining layout and content with a JSON schema.

• Use PDF.js if you need to render and view PDFs in the browser—not create or edit them.

But even with the right tool, developers often run into limitations they didn’t expect—especially when scaling projects or integrating with more complex workflows.

Common Pitfalls When Choosing a PDF Library

Even experienced developers can run into friction when working with open source PDF tools. These libraries are powerful, but they come with trade-offs that aren’t always obvious at first:

• Choosing a rendering library (like PDF.js) when what you really need is generation or manipulation.

• Assuming form support means full interactivity—when most libraries only support basic static fields.

• Over-engineering workflows by chaining multiple libraries, resulting in brittle pipelines and more maintenance.

• Building your own validation or logic layers from scratch—only to realize that dynamic form behaviors aren’t natively supported.

These pitfalls are common not because developers make bad decisions—but because the ecosystem requires compromise. That’s why many teams eventually look for a more cohesive, high-level approach.

What If You’ve Outgrown These Libraries?

Open source PDF libraries are powerful—but they’re also low-level. They give you building blocks, but you still have to assemble the architecture yourself:

• No automatic data syncing

• No responsive layout for forms

• No validation logic or conditional fields

• No workflows or audit trails

• No integration with cloud APIs or backend systems

They’re great if you want to build everything from scratch. But not so great when deadlines, changing requirements, or scale come into play.

Joyfill: A JavaScript PDF Form Filler SDK

If you are looking for the whole shebang, Joyfill gives you:

• A programmable, JSON-based format (JoyDoc) to define forms and logic

• A web-powered rendering engine

• Built-in validation and conditional logic

• An output layer that generates pixel-perfect PDFs

And much more…

While open source PDF libraries can be a solid starting point—especially for developers seeking flexibility and cost efficiency—they often come with trade-offs in terms of maintenance, documentation, and long-term scalability. For teams that need a more streamlined and robust solution, a commercial SDK like Joyfill’s PDF Form Filler SDK offers an elevated path. Designed for developers, it provides a modern way to embed fully functional, customizable PDF forms into web and mobile applications without the overhead of managing low-level rendering or field logic.