About JWT Decoder
Decode JWT tokens to view header, payload, and signature. Validates expiration and shows claim explanations.
Frequently Asked Questions
Is it safe to decode JWTs online?
Yes, our JWT decoder runs entirely in your browser using JavaScript. Your tokens are never sent to any server - all decoding happens locally on your device.
What is a JWT and how does it work?
A JSON Web Token (JWT) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three parts: header, payload, and signature.
What do the common JWT claims mean?
Standard claims include: iss (issuer), sub (subject), aud (audience), exp (expiration), nbf (not before), iat (issued at), and jti (JWT ID).
Can I verify JWT signatures with this tool?
This tool decodes and displays JWT contents but does not verify signatures. Signature verification requires the secret key or public key.
Why is my JWT showing as expired?
JWTs contain an exp (expiration) claim as a Unix timestamp. If the current time is past this timestamp, the token is expired.