A local-first toolbox for developers
A collection of online developer tools — JSON, encoding, crypto, color, text, regex, QR codes and more. Everything runs locally in your browser; your data never leaves your device.
Local processing · no uploads
Popular tools
JSON Formatter
Beautify, minify and validate JSON with live error hints.
Base64 Encode/Decode
Encode and decode Base64 with correct UTF-8 handling.
URL Encode/Decode
Percent-encode and decode URL components.
JWT Decoder
Decode a JWT's header and payload, with expiry hints.
UUID Generator
Generate UUID v4 in bulk, optional uppercase or no hyphens.
Hash Calculator
Compute MD5 / SHA-1 / SHA-256 / SHA-512 digests of text.
Timestamp Converter
Convert Unix timestamps to dates and back (s / ms).
Regex Tester
Test regex live, highlighting and listing all matches.
Color Converter
Convert between HEX, RGB and HSL with a live preview.
QR Code Generator
Generate a QR code from text or a URL, download as PNG.
Password Generator
Generate strong random passwords with a strength meter.
Word Counter
Count characters, words, lines and paragraphs live.
JSON to TypeScript
Infer TypeScript interface/type from JSON. Nested objects get their own interfaces; array element types are merged.
Text Diff
Compare two texts line by line, highlighting additions and deletions.
Base Converter
Convert between binary, octal, decimal and hex (BigInt).
JSON ⇄ YAML Converter
Convert between JSON and YAML, with indent options.