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

Source: Dev.to

The problem

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 routine: 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.

Tools I actually use at 2 am

JSON Tree Viewer

The first tool I built and use most. When a production API returns a massive nested response, I can expand/collapse by depth, search for a specific field, pin the paths I keep checking, and run JSONPath queries (e.g., $.data.users[*].errors) to get exactly what I need.

JSON Compare

“Why does staging return different data than prod?” Paste both JSON payloads and get a diff. It’s smart enough to detect moved array items instead of marking everything as removed + added.

JWT Decoder

“Is this token supposed to have admin scope?” Paste the token and see the header, payload, and expiry instantly.

Base64 / URL Decoder

Some API returns something encoded and I need to know what’s inside—fast, in‑browser decoding.

Timestamp Converter

“Is this 1708531200 in seconds or milliseconds? What time is it actually?” Convert timestamps to readable dates.

Hash Generator & Verifier

Quick SHA‑256 checksums, HMAC verification, and file‑integrity checks.

Key Case Converter

Backend returns user_name but frontend expects userName? Convert all JSON keys with one click.

There are about 40 tools total—including 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 data passing through someone else’s server. Stingr runs 100 % in the browser—open the Network tab and you’ll see zero requests. Hashing uses the Web Crypto API; everything else is plain JavaScript.

How it’s built

• Framework: React + Vite
• Dependencies: Four total, nothing fancy

I built it to solve my own problem, and Claude helped me ship it way faster than I could have alone. It’s an open‑source project:

• Site:
• GitHub: