Skip to content


PDF.js Build Status

PDF.js is a Portable Document Format (PDF) viewer that is built with HTML5.

PDF.js is community-driven and supported by Mozilla. Our goal is to create a general-purpose, web standards-based platform for parsing and rendering PDFs.


PDF.js is an open source project and always looking for more contributors. To get involved, visit:

Feel free to stop by our Matrix room for questions or guidance.

Getting Started

Online demo

Please note that the "Modern browsers" version assumes native support for the latest JavaScript features; please also see this wiki page.

Browser Extensions


PDF.js is built into version 19+ of Firefox.


  • The official extension for Chrome can be installed from the Chrome Web Store. This extension is maintained by @Rob--W.
  • Build Your Own - Get the code as explained below and issue npx gulp chromium. Then open Chrome, go to Tools > Extension and load the (unpackaged) extension from the directory build/chromium.

Getting the Code

To get a local copy of the current code, clone it using git:

$ git clone
$ cd pdf.js

Next, install Node.js via the official package or via nvm. If everything worked out, install all dependencies for PDF.js:

$ npm install


On MacOS M1/M2 you may see some node-gyp-related errors when running npm install. This is because one of our dependencies, "canvas", does not provide pre-built binaries for this platform and instead npm will try to build it from source. Please make sure to first install the necessary native dependencies using brew:

Finally, you need to start a local web server as some browsers do not allow opening PDF files using a file:// URL. Run:

$ npx gulp server

and then you can open:

Please keep in mind that this assumes the latest version of Mozilla Firefox; refer to Building PDF.js for non-development usage of the PDF.js library.

It is also possible to view all test PDF files on the right side by opening:

Building PDF.js

In order to bundle all src/ files into two production scripts and build the generic viewer, run:

$ npx gulp generic

If you need to support older browsers, run:

$ npx gulp generic-legacy

This will generate pdf.js and pdf.worker.js in the build/generic/build/ directory (respectively build/generic-legacy/build/). Both scripts are needed but only pdf.js needs to be included since pdf.worker.js will be loaded by pdf.js. The PDF.js files are large and should be minified for production.

Using PDF.js in a web application

To use PDF.js in a web application you can choose to use a pre-built version of the library or to build it from source. We supply pre-built versions for usage with NPM and Bower under the pdfjs-dist name. For more information and examples please refer to the wiki page on this subject.

Including via a CDN

PDF.js is hosted on several free CDNs:


You can play with the PDF.js API directly from your browser using the live demos below:

More examples can be found in the examples folder. Some of them are using the pdfjs-dist package, which can be built and installed in this repo directory via npx gulp dist-install command.

For an introduction to the PDF.js code, check out the presentation by our contributor Julian Viereck:

More learning resources can be found at:

The API documentation can be found at:


Check out our FAQs and get answers to common questions:

Talk to us on Matrix:

File an issue: