Free JWT Decoder
Free tool to decode and inspect JWT tokens, check expiry, and view claims.
All processing happens in your browser. No data is sent to any server.
What Is JWT?
JWT (JSON Web Token) is a compact token format used to transfer claims between systems, often for authentication and authorization. A JWT is usually sent as a bearer token in API requests.
1. Header
Contains token metadata such as algorithm (for example, HS256).
2. Payload
Contains claims like user id, roles, issued-at (iat), and expiry (exp).
3. Signature
Used to verify integrity so recipients can detect tampering.