Why this exists, and who built it.
Simple Dev Tools is a free collection of browser-based developer utilities — JSON formatting, JWT decoding, hashing, encoding, cron parsing, subnet calculation, and dozens more. Every tool runs entirely client-side. Nothing you paste or upload is sent to a server, logged, or stored — the app works exactly the same with your network tab open and empty.
I'm a full-stack engineer based in Hyderabad, India, and Simple Dev Tools is something I built and maintain entirely on my own — no team, no company, no funding behind it. I build and ship products independently, in public, and this one started the way most of my projects do: I needed a decent JWT decoder that didn't send my tokens to a random server, couldn't find one I trusted, and built it myself.
Everything here is a byproduct of tools I reach for constantly while working on other things. If a tool feels like it was built by someone who actually uses it daily, that's because it was.
Most "online tool" sites for things like JWT decoding or JSON formatting quietly send your input to a server to process it — which is a bad default for anything that touches auth tokens, certificates, internal config, or customer data. This site exists because that shouldn't be the norm. Browsers are fast enough to do almost all of this work locally, so there's no real reason to round-trip it through a backend.
You can verify all of this yourself — open your browser's network tab, use any tool, and confirm there's no outgoing request carrying your input.
New tools ship regularly, guided mostly by what's actually useful in day-to-day dev work rather than chasing every possible utility. If there's a tool you keep wishing existed, tell me — see the contact info below.
Feedback, bug reports, or tool requests — reach out on X (@itzznikhilsai) or check out my other work at nikhilsai.in.