A collection of simple, browser-based utilities. No server required - just open the HTML files.
Converters
- JSON to YAML - Convert JSON to YAML format
- CSV to JSON - Convert CSV with custom delimiters
- Color Converter - HEX, RGB, HSL, HWB, LAB, LCH, OKLAB, OKLCH
- Temperature Converter - Celsius, Fahrenheit, Kelvin, Rankine, Delisle, Newton, Réaumur, Rømer
- Date-Time Converter - ISO 8601, RFC 3339, Unix timestamp, Excel, MongoDB ObjectID
- Timestamp Converter - Unix timestamps with timezone support
- XML ↔ JSON - Bidirectional XML and JSON conversion
Formatters
- HTML Formatter - Pretty print or minify HTML
- JSON Formatter - Pretty print or minify with key sorting
- XML Formatter - Pretty print or minify XML
- YAML Formatter - Pretty print with key sorting
Encoders/Decoders
- Base64 Encoder/Decoder - Bidirectional real-time
- URL Encoder/Decoder - Bidirectional real-time
- HTML Entity Encoder - Bidirectional real-time
- JWT Decoder - Decode and inspect tokens
- Roman Numerals - Convert Roman numerals to numbers and vice versa
Parsers/Analyzers
- URL Parser - Decompose URL into components
- Regex Tester - Test JS regex with highlighting
- Clipboard Viewer - Inspect all clipboard formats and data
- EXIF Viewer - Extract metadata and GPS from images
- IBAN Validator - Validate and parse IBAN numbers with QR-IBAN detection
Other Tools
- Markdown Preview - Live markdown to HTML
- Paste Rich Text - Extract HTML from pasted rich text
- Diff - Compare text with colored output
- OCR - Extract text from images and PDFs (Tesseract.js)
- QR Code Generator - Generate styled QR codes with PNG/SVG download
- Password Generator - Generate secure random passwords with customizable options
Open index.html in a browser, or serve with any static file server.
Filter tools on load with ?q=json query parameter.
See AGENTS.md for coding guidelines.
MIT