JWT Expiry Checker
Show whether a JWT is expired, valid, or missing expiry claims with readable timestamps.
What is JWT Expiry Checker?
Check exp and nbf NumericDate claims in a three-segment JWT. exp is seconds since the Unix epoch, while JavaScript Date uses milliseconds.
How to use JWT Expiry Checker?
Step 1
Paste the JWT token.
Step 2
Review the decoded expiry and issued-at timestamps.
Step 3
Use the status callout to confirm valid, expired, or missing claim states.
Example input / output
An exp of 1700000000 means 2023-11-14T22:13:20Z. It is expired after that instant regardless of the local display timezone. The original issuer's signature must still be verified.
Example input
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTYiLCJleHAiOjE5MTM0NTYwMDAsImlhdCI6MTcwNDAyMzAwN30.signatureCheck the result
- Tokens without an exp claim cannot be evaluated for expiration.
- Clock drift between systems can make borderline tokens appear inconsistent.
Practical developer examples
Check the unit
A millisecond value placed in exp can look far into the future. Compare the issuer's token lifetime with its documented NumericDate format.
Check not-before
A future nbf means the token is not active yet, even when exp has not passed. Investigate clock skew and the issuer's allowed leeway.
Common developer use cases
Timing is checked against the device clock. Missing exp does not prove indefinite validity, and an unexpired token is not an authenticated token.
Common issues
FAQ
Does not expired mean the token is valid?
No. Signature verification, trusted issuer, audience and authorization policy are separate checks.
What happens exactly at exp?
The token is expired when the current time is equal to or later than exp. Server-side leeway, if any, must be defined by your verifier.