JWT Expiry Checker - Free, Instant, No Sign-Up
Overview
Debugging an expired session usually means hunting through opaque cookie values or adding console.log statements. Paste the JWT here and the decoder reads the exp, iat, and nbf claims from the payload and converts Unix timestamps into plain language: Expired 3 days ago, Expires in 47 minutes, or Not valid before Jan 15 08:00 UTC.
How to Use This Tool
Paste your JWT into the input. The expiry panel appears immediately below the payload showing the three time claims. A red badge marks expired tokens; green marks valid ones. No secret key needed to check expiry since the payload is not encrypted.
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PDF Tool →Frequently Asked Questions
What is the nbf claim in a JWT?
The nbf (not before) claim specifies the earliest time the token is valid. A token with nbf set to a future timestamp should be rejected by servers until that time arrives. It prevents tokens from being used before they are intended to be active.
Why does my JWT show as expired even though I just generated it?
Clock skew between the issuing server and your machine can cause this. JWTs are time-sensitive to the second. If the server clock is ahead, the token may appear expired locally. Check the exp value against your system clock.
Can I extend a JWT expiry?
No. JWTs are signed and any modification, including changing exp, invalidates the signature. To get a new expiry, request a fresh token from the issuing server or use a refresh token flow.