JWT Expiry Editor Guide
Edit iat, nbf and exp claims on a JWT and re-sign it without touching JSON by hand.
A short companion for JWT Expiry Editor: when it is useful, what it expects, and what to check before using the result.
What it does
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.
Use the tool
Open JWT Expiry Editor, add the input the tool asks for, run it, and check the output before using it elsewhere.
Input and output
- Input: text.
- Output: text.
- Category: Web.
Privacy and processing
Processing happens locally in your browser. This tool does not upload the input to ilham.dev.
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.
Related guide
For broader background, see Understanding and Debugging JWTs.