I built an open-source, privacy-first PDF toolkit (80+ tools) to replace Adobe. Here is the stack.

Source: Dev.to

The “Why”

If you are a developer, you probably hate uploading sensitive documents (tax forms, contracts, bank statements) to random “Free PDF Merger” websites. You know that “Free” usually means “You are the product.”

I wanted a tool that:

• Runs 100 % locally (files never leave the browser)
• Is Open Source (so I can verify the code)
• Doesn’t suck (clean UI, no ads, no “3 files per day” limits)

So, I built PDFCraft – an MIT‑licensed, client‑side PDF toolkit built with Next.js and WebAssembly.

• Repo:
• Demo:

The Tech Stack

Frontend Framework

Next.js (React) – used for static site generation (SSG) to get SEO benefits and fast initial load times.

Styling

Tailwind CSS – provides a clean, responsive UI that works on mobile.

Core Engine (The Heavy Lifting)

• WebAssembly (Wasm): Runs heavy image and PDF processing logic in the browser at near‑native speed.
• Libraries:
  • pdf-lib – PDF manipulation
  • pdf.js – PDF rendering
  • tesseract.js – client‑side OCR

Architecture: Zero‑Server Processing

The most interesting part of PDFCraft is what it doesn’t have: a backend API for file processing.

Traditional:
User Uploads File → Server (AWS/GCP) Processes it → User Downloads

PDFCraft:
User Selects File → Browser (Wasm/WebWorkers) Processes it → User Downloads

Why this matters for devs

• Privacy: No server sees your files; there’s no database to hack.
• Cost: Hosting is cheap (static files only).
• Speed: No network latency for uploading large files.

Key Features Implemented

PDFCraft started as a simple merger and grew into a suite of 80+ tools. Highlights include:

• Client‑Side OCR: Uses tesseract.js with Web Workers to extract text from scanned PDFs without freezing the main thread.
• Conversion: Convert PDFs to Office formats (Word/Excel) and images (JPG/PNG/HEIC) directly in the browser.
• Security: AES encryption/decryption handled purely on the client.

Self‑Hosting & Extension

Privacy is the main goal, so you can run it yourself:

• Clone the repo and deploy anywhere (Vercel, Netlify, or your own Docker container).
• A Chrome Extension (zip included in the repo) provides quick access without opening a new tab.

Open Source & Roadmap

The project is fully open source under the MIT License. I’m looking for contributors to help with:

• Improving PDF viewer performance for huge files (500 MB+).
• Adding more language support for OCR.

If you’re interested in WebAssembly or PDF manipulation, check out the code!

GitHub: