Powered by DNPR — proprietary PDF 2.0 interpreter (patent pending). Full compliance with the latest PDF standard, DOM-native output. Your files never leave your device.
PDF.js is Mozilla's open-source PDF viewer. It has served the web well for 16+ years. But it was designed for one purpose: displaying PDFs on a canvas element. It was never meant for editing.
PDF.js renders to HTML Canvas — a pixel-based drawing surface originally created by Apple in 2004 for macOS Dashboard widgets, not for PDFs. It became the de facto rendering target because PDF drawing commands map conveniently to Canvas methods — both are immediate-mode drawing systems. But that convenience ends at rendering. Canvas produces pixels, and pixels can't be edited.
PDF.js renders to HTML Canvas — a pixel-based drawing surface. The output is a flat image with no interactive elements.
Editing score: 1/10. The library provides zero editing capabilities. Services must build entire editing layers from scratch on top of it.
A single monolithic worker with no modular architecture. You load everything or nothing.
PDFox.js is a proprietary PDF 2.0 interpreter built from the ground up. It's designed around a single principle: the PDF is an object, not an image — the PDF stream should be directly representable as editable DOM elements.
Text you can click and type. Graphics you can select and move. Images you can reposition. The PDF is the document — not a picture of it.
Modular design — import only what you need. Build a viewer or a full editor, paying only for the capabilities you use.
Built natively on the latest PDF standard — not a retrofit. Enterprise-grade encryption, digital signatures, full Unicode support, and accessibility features.
All performance-critical operations execute at near-native speed via proprietary acceleration.
Same renders to editable DOM, pixel-perfect Canvas, and scalable SVG. Choose the right output for your use case.
Editing score: 8/10. The only engine with built-in inline editing. PDF.js and pdfium both score 1/10.
DOM-Native PDF Rendering is the subject of U.S. Provisional Patent Application #63/997,982. The first patented approach to rendering PDFs directly to editable DOM elements.
A side-by-side comparison of the V1 engine (PDF.js) and V2 engine (PDFox.js) across key dimensions.
| Aspect | V1 (PDF.js) | V2 (PDFox.js) |
|---|---|---|
| Language | Open-source | Proprietary |
| Codebase | Monolithic | Modular |
| Render Target | Canvas only | DOM + Canvas + SVG |
| Editing | None (score: 1/10) | Native inline editing (score: 8/10) |
| Acceleration | Limited | Full proprietary acceleration layer |
| Tree-Shakeable | No | Yes |
| Font Engine | Basic conversion | Native browser rendering |
| BiDi/RTL | Basic (score: 7/10) | Full support (score: 9/10) |
| OpenType Features | Minimal (score: 3/10) | Full support (score: 8/10) |
| Overprint | XFA-only (score: 2/10) | Full support (score: 8/10) |
| PDF Standard | PDF 1.7+ (partial 2.0) | Full PDF 2.0 compliance |
| Encryption | Basic | Enterprise-grade (PDF 2.0) + legacy support |
| License | Apache 2.0 (open-source) | Proprietary (Patent Pending) |
| Maturity | 16+ years | < 1 year |
PDF.js and pdfium were built around older PDF specifications and have gradually adopted newer features over time. The DNPR engine was designed from scratch on the latest PDF 2.0 standard — the most current revision, not a retrofit of older specifications.
PDF 2.0 mandates the strongest encryption standard available. The DNPR engine implements this natively.
PDF 2.0 introduces advanced digital signatures with long-term validation support, replacing deprecated legacy formats. Full signing and verification built in.
PDF 2.0 allows UTF-8 text strings natively, eliminating the legacy PDFDocEncoding limitations. Full Unicode support across all text operations.
DSS enables long-term signature validation by embedding all required certificates, CRLs, and OCSP responses directly in the PDF file.
PDF 2.0's namespace mechanism allows role mapping between standard structure types and custom tags, enabling richer accessibility and semantic markup.
Full validation for the latest archival (PDF/A) and accessibility (PDF/UA) standards.
Across 104 rendering features benchmarked against both PDF.js and pdfium, PDFox.js takes the lead in categories that matter most for editing.
Scores out of 10. Full PDF 2.0 compliance across all rendering categories.
All performance-critical codepaths are handled by DNPR's proprietary acceleration layer at near-native speed.
The only PDF engine that renders directly to editable DOM elements — a patent-pending approach called DNPR. Text is directly editable, graphics are SVG, and the browser handles layout.
Modular design — import only what you need. Build a viewer or a full editor, paying only for the capabilities you use.
Full advanced typography support. Ligatures, kerning, and complex scripts rendered correctly — not approximated.
6.5x Faster — A 15-page PDF opens in ~200ms, down from ~1,300ms in V1.
Explore how PDFox.js is structured as a modular, patent-pending DNPR architecture.
View Architecture