JWT Expiry Editor

About this tool

Load a JWT, edit its iat, nbf and exp claims with date pickers, and re-encode the token. Use the quick +15m / +1h / +1d buttons to extend an expiry, then re-sign with HS256, HS384 or HS512, or strip the signature entirely for local testing. Everything runs in the browser.

Questions

The signature no longer verifies after editing — is that a bug?
No. Changing any claim changes the signed data. Re-sign with the same secret and algorithm the issuer used, or the token will be rejected.
Can it sign with RS256 or ES256?
Not yet. This tool focuses on HMAC secrets for quick testing; use the JWT Encode tool for PEM-based algorithms.