Free, in-browser PDF editor
Privacy-first PDF editor running locally, but Smallpdf and PDF24 already do this.

Client-side PDF toolkit when most competitors upload your files to their servers.
Privacy-conscious users and professionals handling sensitive documents
Smallpdf · ILovePDF · PDF24
I built it because when people search Google for common PDF tasks, many of the tools they find upload documents to a server. I wanted an option that keeps files local instead.
I posted an earlier version on HN last spring: https://news.ycombinator.com/item?id=43880962
At the time it only supported a small set of features. Over the last 10 months I rebuilt large parts of it and expanded it to nearly 40 tools, including several ideas that came from comments in that earlier thread.
There is also now a desktop app for macOS, Windows, and Linux, plus a CLI/SDK for developers.
Privacy-first PDF editor running locally, but Smallpdf and PDF24 already do this.
Edits actual PDF text streams locally instead of just overlaying new text boxes.
Local-first PDF editing that respects your filesystem is a rare find today.
Free browser-only PDF tools with audit trails, but iLovePDF and CyberChef already dominate.
Edit scanned PDFs visually without OCR, like moving layers in Photoshop.
Zero-server processing inside the browser is the clever bit — Web Workers + pdf-lib/PDF.js lets you compress, merge, split and convert large PDFs without uploading sensitive files. The app also supports offline use and multiple languages, but the repo is early-stage with minimal community traction, so it’s useful now for cautious users or integrators rather than a drop-in replacement for mature SaaS players.