# JWT Expiry Editor Guide

Edit iat, nbf and exp claims on a JWT and re-sign it without touching JSON by hand.

- Tool: https://ilham.dev/tools/jwt-expiry-editor/
- Guide URL: https://ilham.dev/guides/jwt-expiry-editor/
- Tool guides index: https://ilham.dev/guides/tools/
- Broader guide: Understanding and Debugging JWTs (https://ilham.dev/guides/jwt-debugging/)

## 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 https://ilham.dev/tools/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.