JWT Debug Playbook
Most JWT failures come from timing, key mismatch, and algorithm expectations rather than token format itself.
3-step triage
- Does header alg match backend verification algorithm?
- Are exp, nbf, and iat aligned with server time?
- Is secret/public key environment correct (no prod/test mismatch)?
For quick validation, use JWT Decoder / Signer.
Editorial Note
This guide is maintained around real workflows and reviewed regularly. The goal is not keyword stuffing, but clearer technical decisions you can apply.
Last reviewed
Editorial owner
WebkitZero Editorial
Latest change log
2026-04-20
Initial version published with a step-by-step workflow for JWT signature and expiry issues.