Hey Product Hunt 👋 I'm the maker of DevNest. I kept pasting JWTs, API responses and config files into random online tools while debugging — and realised I had no idea whether any of them sent that data to a server. Some of those tokens were live sessions. So I built DevNest: eight tools I use every week, all running entirely in the browser. There's no backend that could receive your data. A few things I'm proud of: 🔐 JWT Decoder shows expiry as "expires in 2 hours / expired 3 days ago" — and clearly warns that decoding isn't verifying 🧪 Regex Tester runs in a Web Worker with a timeout, so a catastrophic pattern like (a+)+$ can't freeze your tab #️⃣ Hash Generator does MD5 → SHA-512 for text or files, with HMAC and a "compare with expected checksum" box 🧾 JSON Formatter tells you the exact line and column of an error, with a "jump to error" button It's free, needs no sign-up, and works on mobile. What tool should I add next? I'm considering JSON ↔ CSV, a cron expression explainer and a diff checker — I'd love to hear what you use most.

DevNest

8 private developer tools that never leave your browser

8 private developer tools that never leave your browser