SafetyPDF is a small tool I built for people who care about privacy when sharing documents.
Most online PDF compressors upload your file to a remote server. SafetyPDF does the opposite:
The compression engine loads as a WebAssembly module inside your browser
All parsing, optimization, and output stay in browser memory
No document content is sent to my servers – you can even go offline after the engine loads and keep compressing
A typical compression run in SafetyPDF looks like this:
You open a PDF through the browser’s File API – no upload requests are made
The WebAssembly runtime reads and optimizes the file entirely in memory
The compressed PDF is returned as a Blob and downloaded client-side
Temporary buffers and object URLs are cleaned up after the download
For transparency, each load prints a WebAssembly hash to the DevTools console so you can verify which build you’re running. Analytics only record anonymized session counts — never file names or document content.
I built this as a learning project in WebAssembly and local-first design, and it has already been used by a few hundred people. If you try it and find it helpful, I’d love to hear your feedback — and if you feel like it, you can always buy me a coffee here as a tip. ☕
🔗 You can try it here: safetypdf.com