mozilla/pdf.js

🔥 Hot★ 53,333JavaScriptAudience · developerComplexity · 3/5ActiveLicenseSetup · easy

Mindmap

mindmap
  root((repo))
    What it does
      Renders PDFs in browsers
      No plugins needed
      Uses Canvas drawing
    How it works
      Parses PDF bytes
      Main thread display
      Worker thread parsing
    Use cases
      Document management
      Contract signing
      Digital libraries
      Embedded viewers
    Tech stack
      JavaScript
      HTML5 Canvas
      Web Workers
      Node.js build
    Audience
      Web developers
      App builders
      Document platforms

mindmap root((repo)) What it does Renders PDFs in browsers No plugins needed Uses Canvas drawing How it works Parses PDF bytes Main thread display Worker thread parsing Use cases Document management Contract signing Digital libraries Embedded viewers Tech stack JavaScript HTML5 Canvas Web Workers Node.js build Audience Web developers App builders Document platforms

Things people build with this

USE CASE 1

Embed a PDF viewer directly into your website without requiring users to download files or install plugins.

USE CASE 2

Build a document management platform that displays contracts, invoices, or reports inline in the browser.

USE CASE 3

Create a digital library or archive where users can browse PDFs without leaving your app.

USE CASE 4

Add PDF preview functionality to a web application using the pdfjs-dist npm package.

Tech stack

JavaScriptHTML5 CanvasWeb WorkersNode.jsGulp

Getting it running

Difficulty · easy Time to first run · 5min

Use freely for any purpose, including commercial use, as long as you keep the copyright notice and license text.

In plain English

PDF.js is an open-source library created by Mozilla that lets web browsers display PDF files using only JavaScript and standard web technologies, no plugins, no Adobe Reader, no extra software required. PDF stands for Portable Document Format, a file format commonly used for sharing documents that look the same on any device. The way it works is by parsing the raw bytes of a PDF file entirely inside the browser. PDF.js reads the file structure, interprets text, fonts, images, and vector graphics, then renders them onto an HTML5 Canvas element, essentially drawing the page on screen the same way a game might draw graphics. Because PDF rendering can be slow and complex, the library splits its work across two scripts: pdf.js handles the display layer you see, while pdf.worker.js runs the heavy parsing work in a background thread so the main page stays responsive. You would use PDF.js whenever you want to embed PDF viewing directly into a website or web application without forcing users to download files or rely on browser plug-ins. It powers the built-in PDF viewer in Firefox and is available as a Chrome extension. Developers can also integrate it into their own applications using the pdfjs-dist package from npm, the standard JavaScript package registry. PDF.js is particularly useful for document management platforms, online editors, and any web app that needs to show PDFs inline, from contract signing tools to digital libraries. The tech stack is pure JavaScript, with Node.js and the Gulp build tool used to bundle and compile the source files for production. No server-side component is required; everything runs inside the user's browser.

Copy-paste prompts

Prompt 1

How do I embed a PDF viewer in my React app using pdf.js? Show me a basic example with pdfjs-dist.

Prompt 2

I want to display a PDF file from my server in a web page. Walk me through setting up PDF.js with a Canvas element.

Prompt 3

How does PDF.js use Web Workers to keep the page responsive while rendering large PDFs?

Prompt 4

Can I customize the look of the PDF viewer toolbar in PDF.js? What options are available?

Prompt 5

Show me how to integrate PDF.js into a Next.js project and handle file uploads.

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Generated 2026-05-18 · Model: sonnet-4-6 · Verify against the repo before relying on details.