JWT Parser

JWT claims are pieces of information asserted about a subject. They are the key-value pairs in the JWT payload. Claims can be registered (standardized names like iss, sub, exp), public (registered in the IANA JSON Web Token Claims registry), or private (custom claims agreed upon by the parties using the token).

Registered claims are predefined by the JWT specification (RFC 7519) and have standardized meanings, such as iss (issuer), sub (subject), exp (expiration). Custom (private) claims are application-specific and can be any key-value pair agreed upon by the token producer and consumer, like user_role, tenant_id, or department.

The exp claim contains a Unix timestamp (seconds since January 1, 1970 UTC) representing when the token expires. To check if a token is expired, compare the exp value with the current Unix timestamp. If the current time is greater than exp, the token has expired. This parser automatically converts exp to a human-readable date and shows the expiration status.