About DevTools Lab
Why this site exists and how it's built.
DevTools Lab is a small, opinionated collection of developer utilities focused on day-to-day engineering tasks: formatting JSON, cleaning CSV, converting YAML, and testing regular expressions.
Every tool is designed around three principles: privacy (browser-only), speed (instant, no network round-trip), and clarity (minimal, distraction-free UI).
Special focus is given to the Japanese engineering ecosystem — for example, CSV ⇄ Shift-JIS conversion and mojibake detection are first-class features.
The site is open-source and built with Next.js 14, TypeScript and Tailwind CSS, and statically generated for maximum performance.