data.day
← Tools

JWT Debugger

Decode a JWT to view header, payload, and signature locally (no secret validation).

beta browser

Decode a JSON Web Token (JWT) locally to inspect header and payload claims (including iat/nbf/exp as readable dates) and view the signature segment—without validating the secret. Useful for debugging auth flows, expiration issues, and claim shape mismatches. Runs client-side with no tracking, no uploads, and no storage.

Privacy: inputs stay on your device.

Run it

Runs locally in the browser. No tracking. No data stored.