JWT Decoder — Free Online JSON Web Token Decoder

JSON Web Tokens (JWT) are the de facto standard for stateless authentication in modern web applications. After a user logs in, the server issues a JWT that the client includes in the Authorization header of subsequent requests (Authorization: Bearer <token>).

A JWT has three parts separated by dots. The header specifies the token type (JWT) and the signing algorithm (e.g., HS256 for HMAC-SHA256 or RS256 for RSA). The payloadcontains claims — registered claims like sub (subject), exp (expiration),iat (issued at), and custom claims like roles or email. The signatureis computed from the header and payload using the server's secret or private key.

The payload is Base64URL-encoded, not encrypted. Anyone with the token can read its claims. Never put passwords or sensitive personal data in the payload. A trusted verifier must check the signature.

Try the sample token and inspect its Header and Payload tabs. This decoder reads time claims but does not verify a signature, issuer, audience, or revocation. A future expiry alone cannot establish trust.