I built 342 browser-native dev tools - here's why everything runs client-side

I built 342 browser-native dev tools — here's why everything runs client-side

Over the last few months I quietly built ZeroServer.tools — a suite of 342 free developer utilities. JSON formatter, Base64 encoder, hashing, JWT decoder, regex tester, image compressor, PDF tools, CSS generators, calculators, converters, and a lot more.

But the design constraint I imposed from day one is what made this interesting to build: every single tool runs 100% in your browser. No backend. No server calls. Nothing you type ever leaves your device.

Here's why I made that choice — and how the architecture works.

The problem I kept running into