Building PDFLince: A Privacy First PDF Toolkit
Building PDFLince
PDFLince was born from a simple frustration: every online PDF tool asks you to upload your sensitive documents to a remote server. Contracts, financial records, medical files: all passing through infrastructure you don't control.
I decided to build the alternative.
Visit PDFLince | View Source Code on GitHub
The Core Idea
What if all PDF processing happened entirely in your browser? No file ever leaves your device. No server receives your data. The heavy lifting runs locally via Web Workers, keeping the UI responsive while manipulating large files.
Architecture
PDFLince is built with Next.js 15 (App Router) and TypeScript, using a static export architecture (output: "export") that achieves perfect 100/100 Lighthouse scores. The PDF manipulation engine is powered by pdf-lib, running inside dedicated Web Workers to prevent UI blocking.
Key features include:
- Merge: Combine multiple PDF files into one
- Compress: Optimize large PDFs for sharing
- Split & Extract: Pull specific pages from a document
- Convert: PDF to Images and Images to PDF
The Zero-Server Promise
This wasn't just a technical decision: it was a philosophical one. In an era where every SaaS product wants to process your data on their servers, PDFLince takes the opposite approach. Your files stay on your machine. Period.
The entire application works offline once loaded. There is no backend, no database, no analytics on file content.
Open Source
PDFLince is MIT licensed and fully open source. Tech Stack: Next.js, TypeScript, Tailwind CSS, pdf-lib, PDF.js, Web Workers, Geist font.