Regex tester
Type a pattern and flags to highlight matches in the test string in real time. Capture groups and named groups are listed for every match, and there's a replace preview using $1 etc. Runs entirely in your browser.
Related tools
JWT decoder
Paste a JWT and break it down into Header / Payload / Signature. Numeric claims like exp / iat / nbf are translated into human-readable timestamps. No signature verification — purely for inspection. Runs entirely in your browser.
JWT signature verify
Verify a JWT signature using WebCrypto — supports HS / RS / PS / ES with SHA-256/384/512. Paste an HMAC secret for HS*, or an SPKI PEM / JWK public key for RSA / ECDSA. exp / nbf are checked alongside the signature. Nothing leaves your browser.
Text diff viewer
Compare two texts line by line. Supports inline and side-by-side views, word-level highlighting, and ignoring surrounding whitespace. Runs entirely in your browser.