JWT Expiration Checker
Check whether a JWT is expired, when it expires, and its full validity window — locally, without verifying or transmitting the token.
Processed locally in your browser — nothing is uploaded.
JWT Expiration Checker
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Decoding does not verify the signature. Anyone can create a token with any contents — a decoded JWT proves nothing about who issued it or whether it was tampered with. Always verify signatures server-side before trusting claims.
About JWT Expiration Checker
Paste a JWT and instantly see whether it is expired, how long until it expires (or how long ago it did), and its complete validity window from the iat, nbf, and exp claims.
This checks timestamps only. It does not verify the signature, so a token that looks valid here may still be rejected by a server — and a forged token can claim any expiry it likes.
Common uses
- Debug 401 errors caused by expired access tokens
- Check how much lifetime a freshly issued token has
- Verify that refresh logic issues tokens with the expected TTL
Limitations
- Signature is NOT verified — expiry math says nothing about authenticity
- Tokens without an exp claim never expire by RFC 7519; the tool tells you when that's the case
Frequently asked questions
Does checking my token's expiration upload it anywhere?
No. The token is decoded and its timestamps compared in your browser; nothing is sent to or stored on a server. Since a valid token grants access to whoever holds it, keeping it on your device is the safe way to inspect it.
How do I find out when a JWT expires?
Read its exp claim, which is a Unix timestamp in seconds per RFC 7519. This tool shows exp, nbf, and iat as UTC and local dates, plus a live countdown to (or since) expiry that updates every second.
What happens if a JWT has no exp claim?
By RFC 7519 the exp claim is optional, and a token without one never expires on its own. This tool flags that case explicitly, since a non-expiring token is a security risk if it leaks — the server would have to revoke it some other way.
Why is my token 'not yet valid'?
Its nbf (not before) claim is in the future, meaning servers must reject it until that moment. This usually points to clock skew between the issuing server and your machine, or a token deliberately issued for later use.
Why does the server reject a token this tool says is not expired?
Expiry is only one check. Servers also verify the signature, the aud and iss claims, and sometimes a revocation list — this tool does none of that, and a few seconds of clock skew can also make a nearly-expired token fail server-side.