JWT Decoder — Inspect Header, Payload & Claims
Paste a JWT and inspect its header, payload, and signature. Standard claims like exp, iat and nbf are shown as human-readable timestamps, and expired tokens are flagged. This tool decodes only — signature verification requires the signing key and is out of scope.
Note: This decodes claims only. Signature validity is not verified — that requires the signing secret or public key.
Input0 chars · 0 lines
Output
Result will appear here.// Features
- ▸Split header, payload, and signature
- ▸exp / iat / nbf shown as human timestamps
- ▸Expired token warning banner
- ▸Never transmitted — decoded locally
// How to use
- 01Paste your JWT into the input pane.
- 02Read the decoded header and payload.
- 03Check the expiry banner and standard claims.
// FAQ
Your data never leaves your browser. This tool runs 100% locally — no upload, no logging, no analytics on your inputs.