I Built Myself a Debugging Toolkit — Made With My Claude Friend, Sharing With You

Yuval Atia — Sat, 21 Feb 2026 20:07:30 +0000

I spend a lot of time debugging things in production. Weird JSON responses, tokens that don't look right, timestamps that make no sense, hashes that need verifying.

Every time, it's the same thing — google "base64 decode online", paste sensitive production data into some random website, get the answer, move on. It always felt wrong.

So I built Stingr — a toolkit for the stuff I actually need during debugging. Everything runs in your browser, nothing gets sent anywhere. I made it together with Claude (yes, the AI —
we're friends now 🤖❤️) and figured I'd share it in case it helps you too.

👉 stingr.dev

The tools I actually use at 2am

JSON Tree Viewer — this is the one I built first and use most. When a production API returns a massive nested response and I need to find what's wrong, I need to expand/collapse by
depth, search for a specific field, pin the paths I keep checking. Recently added JSONPath queries too, so I can do $.data.users[*].errors and get just what I need.

JSON Compare — "why does staging return different data than prod?" Paste both, get a diff. It's smart enough to detect moved array items instead of marking everything as removed +
added.

JWT Decoder — "this token is supposed to have admin scope, does it?" One paste, header + payload + expiry right there.

Base64 / URL Decoder — some API just returned something encoded and I need to know what's in it. Fast.

Timestamp Converter — is this 1708531200 in seconds or milliseconds? What time is it actually?

Hash Generator & Verifier — quick SHA-256 checksums, HMAC verification, file integrity checks.

Key Case Converter — backend returns user_name but frontend expects userName? Convert all JSON keys with one click.

There's about 40 tools total — formatters, regex tester, cron parser, text diff, generators — but the ones above are my daily drivers.

Why it's all client-side

When I'm debugging production, I'm dealing with real user data. I don't want that going through someone else's server. Stingr runs 100% in the browser — open the Network tab and check,
zero requests. Hashing uses the Web Crypto API, everything else is plain JS.

How it's built

React + Vite, four dependencies total. Nothing fancy. I built it to solve my own problem and Claude helped me ship it way faster than I could have alone. Honestly a great experience
building together.

It's open source: github.com/yuval-atia/stinger

If it saves you even one "let me google base64 decode" during your next incident, I'm happy. And if you have ideas for tools you'd want — open an issue, I'm actively adding stuff.

Forem: Yuval Atia

I Built Myself a Debugging Toolkit — Made With My Claude Friend, Sharing With You