2 open source tools compared. Sorted by stars — scroll down for our analysis.
| Tool | Stars | Velocity | Language | License | Score |
|---|---|---|---|---|---|
pdf.js PDF Reader in JavaScript | 53.0k | — | JavaScript | Apache License 2.0 | 82 |
react-pdf Create PDF files using React | 16.5k | +8/wk | TypeScript | MIT License | 79 |
pdf.js is the PDF renderer that Firefox uses, and it's the reason you can view PDFs in your browser without Adobe Reader. Pure JavaScript, no plugins, renders directly to Canvas or SVG. It's the default PDF viewer for the web. If you're building a web app that needs to display PDFs — document management, contract signing, report viewing — pdf.js is the starting point. PSPDFKit and PDF Tron are the commercial options with annotation, form filling, and signature features built in. React-PDF wraps pdf.js for React components. Commercially, Adobe's PDF Embed API is free but adds a dependency. 53K+ stars, maintained by Mozilla, and running in production in literally billions of browser sessions. The rendering quality handles most PDFs correctly. The catch: pdf.js renders PDFs — it doesn't edit them. No built-in annotation, form filling, or digital signatures. Complex PDFs with advanced features sometimes render imperfectly. Performance on very large documents (500+ pages) can lag. And if you need server-side PDF processing (generation, manipulation), you want a different tool entirely — look at pdf-lib or Puppeteer.
react-pdf lets you build PDFs the same way you build React components. Document, Page, Text, View — if you know React, you already know the API. Generate invoices, reports, or contracts with the same component model and styling approach you use for your UI. Works in browser and Node.js. pdfkit is the lower-level Node.js alternative with more control but imperative code. puppeteer can render HTML to PDF but needs a headless browser — heavy for server-side generation. Commercially, DocRaptor and Prince XML handle complex PDF layouts better. Use react-pdf if your app already lives in React and you need programmatic PDF generation. Invoices, receipts, certificates — anything with structured, repeatable layouts. MIT-licensed and actively maintained. The catch: complex layouts hit limitations fast. CSS support is partial (no CSS Grid, limited Flexbox), and if your PDFs need pixel-perfect reproduction of web pages, you'll fight the renderer. For those cases, puppeteer or a headless Chrome approach is more reliable.