I built a privacy-first alternative to jwt.io, regex101 and every other dev tool that phones home

The dirty secret of online dev tools Every dev tool lives on a different website. jwt.io for JWT decoding. regex101 for regex testing. Some random site for JSON formatting. Another for diff checking. Another for curl → code. Another for SQL formatting. You end up with 10 bookmarks, 10 different UIs, and 10 different servers that just received your most sensitive data — and you never think twice about it. I didn't either. Until I did. What actually happens when you use these tools Let's take jwt.io as an example. Your JWT contains: Your auth algorithm Your user ID Your roles and permissions Your token expiry Sometimes your email, name, org ID When you paste it into jwt.io — it hits their server. It's in their request logs. Maybe forever. The same goes for regex101. Your regex patterns often encode business logic — validation rules, data formats, internal naming conventions. That goes to their database. And every online JSON formatter, diff checker, SQL tool, .env checker you've ever used? Same story. You're not just sharing data. You're sharing the shape of your system. Most of the time nothing bad happens. But "most of the time" is a terrible security posture for a developer who knows better. I got tired of it The more I thought about it, the more it bothered me. I was pasting production JWTs. Real API keys. Actual .env files with database URLs. Into random websites I knew nothing about. So I built DevTab - devtab.in One tab. 110+ dev tools. Zero server calls. Everything runs 100% in your browser via client-side JavaScript and WebAssembly. Open DevTools → Network while using it. Nothing fires. That's not a marketing claim. It's verifiable in 10 seconds. What's inside JSON tools JSON formatter & validator — real-time, error highlighting with line numbers JSON minifier JSON stringify & parse JSON → TypeScript / Pydantic / Go / Zod types Auth & security JWT decoder — header, payload, expiry countdown, issued-at in human time. Zero network requests. .env diff checker —