JSON Formatter
Pretty-print, validate, and minify JSON. Errors report the exact line and column. Everything runs locally — paste API keys or tokens safely.
JWT Decoder
Decode the header, payload, and claims of a JSON Web Token. Expiry and issued-at times are resolved to human-readable dates. Decoding only — the token is never sent anywhere.
Base64
Encode and decode Base64, fully Unicode-safe (emoji and multibyte text included). Toggle URL-safe alphabet for tokens and query strings.
Unix Timestamp Converter
Convert between Unix time and human dates in both directions. Seconds vs. milliseconds are auto-detected. Includes ISO 8601, UTC, local, and relative time.
UUID v4 Generator
Generate cryptographically-random RFC 4122 v4 UUIDs in bulk. Formatting options for uppercase and brace-wrapped output.
Hash Generator
Compute SHA-1, SHA-256, SHA-384, and SHA-512 digests of any text as you type, using the browser's native WebCrypto engine.
Regex Tester
Test a JavaScript regular expression against sample text. Matches are highlighted live and every capture group is broken out. Runs entirely in your browser.
URL & Query String
Percent-encode or decode URLs and components, and break any query string into a readable key/value table. Handy for debugging redirects, OAuth callbacks, and tracking params.
Text Diff
Line-by-line comparison of two blocks of text using a longest-common-subsequence diff. Added lines are green, removed lines are red — all computed locally.