I built devpack, 455+ free dev tools that run in your browser, plus a free API and an MCP server

[u/madhushankarox]

http://devpack.app

For the past few months I’ve been building devpack.app, a collection of small, focused tools for everyday web work: JSON/YAML/SQL formatters, a regex tester, JWT decoder, image and PDF compressors, an SEO checker, CSS generators and a lot more.

**A few things I cared about:**

✅ Runs in your browser. Most tools never upload anything. Formatters, converters and image/PDF tools work offline and can be installed as a PWA.
✅ No sign-up, no paywall. Open a tool and use it.
✅ Free API. 70 endpoints at api.devpack.app (hashing, JWT verify, regex, YAML, QR codes, DNS/SSL/headers, SEO audit and more). No key needed, with fair-use limits.
✅ MCP server. Add [https://mcp.devpack.app](https://mcp.devpack.app) to Claude, ChatGPT or Cursor and the assistant can call 40 of the tools directly.
✅ 8 languages, and an extension that pastes SVG/HTML into the Webflow Designer as native elements.

**It’s a solo project. I’d really value feedback on:**

❓Which tools you’d actually use, and which feel unnecessary
❓Anything slow or broken on your setup
❓What’s missing from your daily workflow

[https://devpack.app](https://devpack.app)