9 free developer tools that run 100% in your browser — nothing ever uploaded to a server. → JSON Formatter & Validator → JSON Diff (compare two JSONs instantly) → JWT Decoder → Base64 Encoder/Decoder → Regex Tester → Timestamp Converter → Color Picker & Converter → UUID Generator (v4, v1, v7) → QR Code Generator No login. No ads. No paywalls. Just tools.