I built a collection of file conversion and PDF tools that process everything client-side. No uploads, no server-side processing. Files never leave your browser.

Site: https://practicalwebtools.comThe core tools:

- PDF to/from Word, Excel, PowerPoint, images - Image conversion (JPG, PNG, WebP, HEIC, GIF, BMP) - Audio conversion (MP3, WAV, FLAC, OGG, M4A) - PDF editing (split, merge, sign, redact) - File compression, hash generation - Some financial calculators (FIRE planning, SaaS metrics, etc.)

There's also an AI chat that connects to Ollama on localhost — genuinely local, no fallback to cloud APIs.

Tech: Next.js, WebAssembly for the heavy lifting, ffmpeg-wasm for audio.

The PDF stuff uses pdf-lib plus some custom WASM modules.Tradeoffs I'm still working through:

ffmpeg-wasm is ~25MB, so I lazy-load it. Still painful.

Safari's WASM memory limits cause issues with large files.

Mobile performance is inconsistent.

Happy to answer questions about the implementation or get told why my architecture is wrong.