- JSON Formatter & Validator
Pretty-print, minify or validate JSON and get the exact line and column of the error.
- UUID v4 Generator
Generate up to 100 random version-4 UUIDs at once, copy as list or JSON.
- Unix Timestamp Converter
Turn epoch seconds or milliseconds into a readable date, and back again in your timezone.
- Base64 Encode / Decode
UTF-8 safe Base64 both ways, with a byte counter and one-click copy.
- Regex Tester
Test a JavaScript regular expression and see every match with index and capture groups.
- URL Encoder / Decoder
Percent-encode a value or a whole URI, decode %XX back, and build clean query strings.
- CSV Dedupe
Remove duplicate rows from a CSV by any column, keeping the first or the last copy. Runs offline.
- Hash Generator
SHA-1, SHA-256 and SHA-512 of any text, hex and base64, computed locally with WebCrypto.
- JWT Decoder
Read a token's header and payload, see exp/iat as real dates, and remember the signature is not verified here.
- Color Converter
HEX, RGB and HSL both ways, with a live swatch and the WCAG contrast numbers next to it.
Why browser-only
Pasting a token, a config file or a customer record into a random website is how secrets leak. These pages have no backend: the JavaScript runs locally and nothing is sent anywhere.