Martin von WysieckiDeveloper Tools
Developer Tools
Free, privacy-friendly developer utilities. Everything runs in your browser — no data leaves your device.
JSON Formatter
Format, minify, and validate JSON with syntax highlighting and error detection.
Base64 Encoder/Decoder
Encode and decode Base64 strings with full UTF-8 support.
Regex Tester
Test regular expressions with real-time match highlighting.
Cron Explainer
Translate cron expressions into human-readable schedules.
JWT Decoder
Decode JWT tokens and inspect header, payload, and claims.
Color Converter
Convert between HEX, RGB, and HSL color formats.