JWT time claims
JWT Expiry Checker
Paste a JWT to inspect exp, iat and nbf, see readable timestamps and determine whether the token is expired or not active yet.
Processed locally in your browser. The token is not sent to a decoding API.
How JWT expiration works
exp is a NumericDate after which a JWT should no longer be accepted.
nbf prevents acceptance before a specified time, while iat records when the token was issued.
Expiration checking is separate from signature, issuer and audience validation.
Recommended JWT expiration guides
These are the guides I use when a time claim looks suspicious or a token is already expired.