I like to make things for fun and profit
DraftPDF is a free PDF editor that runs entirely in your browser. It's a full editor — think Bluebeam or Acrobat Pro — not just a collection of one-off tools. You get annotation tools, measurement tools, form filling, digital signatures, redactions, page management, and more all built into the editor. Everything runs locally on your computer using using the open source PDFium library, so your files never leave your device.
