I've been building this on and off for the past year - it started because I got tired of "free" PDF tools that upload your files to who-knows-where or watermark page 2.

Everything runs client-side: a PDF suite (edit/merge/split/sign/OCR), image and audio converters, 200+ calculators, and some AI tools that lean on local models where possible. No accounts, no file size gates, and it works offline once installed (PWA).

The webdev-relevant bits: most of the heavy lifting is WASM (ffmpeg.wasm, tesseract), plus service workers for offline. Honestly the hardest part was memory management on large files in Safari.

Would genuinely like feedback - especially on what tools are missing. If you want to poke at the audio/video side, https://practicalwebtools.com/studio is the fun part.