A collection of handy browser-based calculator tools, live at laskurit.pomeranssi.fi.
All calculations run locally in the browser — no data is sent to any server, so you can safely calculate password hashes and other sensitive values.
- Time & dates — date arithmetic, timestamps, name days
- Numbers — binary, hexadecimal, octal conversions
- Identifiers — Finnish national ID (hetu) generation/validation, company IDs, bank references
- Colors — color conversions and analysis
- Byte sizes — byte/KB/MB/GB conversions
- Links — URL encoding/decoding and manipulation
- Data pipeline — chainable text/binary operations: encoding (Base64, hex, URL, JWT decode), text transforms (ROT-N, case, sort, trim, unique), formatting (JSON, XML), hashing (MD5, SHA-*), compression (gzip, deflate), and display (hex dump, image/SVG preview, statistics). Supports text input, file drag-and-drop, and URL fetch. Operations are drag-and-drop reorderable with per-operation configuration.
- Cryptography — MD5, SHA-1, SHA-256, SHA-512 hashing
- Pixel density — DPI/PPI calculations
- UUID — validation and UUID v7 timestamp parsing
- Dark mode — system, light, and dark theme support
yarn # Install dependencies
yarn start # Dev server at http://localhost:3000yarn build # Production build (output in dist/)
yarn test # Run tests
yarn lint # ESLint + TypeScript type checking
yarn fix # Auto-fix ESLint issues
yarn deploy # Build and deploy to production- React 19 + TypeScript 5
- Tailwind CSS 4 + shadcn/ui components
- Vite 7 (build & dev server)
- Vitest (testing)
- @dnd-kit (drag-and-drop)