Real-world workflow
Use CaseDebug Expired JWT from API Response
Paste an access token into JWT Decoder to confirm exp/nbf claims when an API returns 401 Unauthorized.
16 August 2026 By Tools.Town Team 5 min read
Steps
- Copy the Bearer token from the failing request (DevTools → Network → Authorization header). Prefer a non-production token when possible.
- Open JWT Decoder.
- Paste the token; inspect payload
exp/nbf/iatagainst current time. - If expired, refresh the token with your auth flow — don’t “fix” by editing claims without re-signing.
- For architecture context, read JWT vs session cookies.
Related
Frequently Asked Questions
Is decoding a JWT the same as verifying it?
No. Decoding reads Base64URL segments. Signature verification needs the correct key/algorithm on a trusted verifier.