Zero-Knowledge Architecture

How ModernPDF
keeps your files safe

Your documents never touch our servers.

AI features send extracted text to Anthropic — never the original file.

Start Using Tools — Free Compare to Others

Three steps. Files stay local.

Processing happens in your browser — not on our servers.

1

Select your file

Your PDF loads directly into your browser's memory. It never leaves your device.

2

Process locally

JavaScript and WebAssembly do all the work right in your browser.

3

Save the result

Download your processed file. Close the tab — nothing remains.

The difference is clear

Other tools require trust. We require nothing.

Cloud-based tools

Smallpdf, iLovePDF, Adobe

  • Files uploaded to their servers
  • Processed on remote infrastructure
  • Stored temporarily (or longer)
  • Account required for full access

ModernPDF

Zero-knowledge by design

  • Files stay on your device
  • Processed entirely in your browser
  • Nothing stored anywhere
  • Free to start

Open source stack

Every library is auditable. No proprietary black boxes.

Rendering
PDF.js
Mozilla
Editing
pdf-lib
MIT License
OCR
Tesseract.js
WebAssembly
Generation
jsPDF
Client-side

AI-powered tools

Some tools use AI. Here's exactly what happens with your data.

OCR

100% local

Text recognition runs entirely in your browser via Tesseract.js WebAssembly. Supports 100+ languages. Zero network requests.

Translate & SafeRedact

Text sent to API

Text is extracted locally, then sent to Anthropic's Claude API for processing. Your original PDF files are never uploaded.

Ready to try it?

No upload required. Just open and use — everything runs in your browser.

Open PDF Tools