Identity · Local browser tool
JWT Decoder and Time Claim Checker
Decode JWT header and payload locally and interpret exp, nbf and iat time claims without pretending to verify the signature.
Use the tool
Enter only data you are authorised to inspect. The result is a focused technical check, not a certification or full vulnerability assessment.
What it checks
Clear scope. Reproducible output.
- Base64url and JSON structure
- Algorithm and token-type signals
- Expiry and not-before timestamps
Questions
Does JWT Decoder and Time Claim Checker upload my input?
No. The working tool runs in the current browser tab. Avoid browser extensions or shared devices when handling sensitive material.
Does a passing result prove my system is secure?
No. It proves only the checks described on this page against the input you supplied. Server behaviour, business logic and runtime vulnerabilities require separate authorised testing.
Why is the result different from a live scanner?
This tool analyses pasted or local data. A live scanner observes network responses, DNS, TLS and redirects, so its evidence and scope are different.