codetools.run is a collection of 47+ developer utility tools that run entirely in your browser. No signups, no server calls, no data leaves your machine. Format JSON, debug JWTs, test regex, generate UUIDs, convert timestamps, minify CSS/JS, encode Base64, generate QR codes, build CSS gradients, and much more. Every tool is free, fast, and privacy-first. Your data stays in your browser. Always. Built with Next.js, open to feedback. New tools added regularly.