JWT Decoder - Debug and Verify JSON Web Tokens
Decode, Inspect and Verify JWTs locally in your browser.
Paste your JWT here (e.g., eyJhbGci...)
How the JWT Decoder Works
This tool decodes the Base64Url-encoded parts of a JSON Web Token (JWT) into readable JSON. It splits the token into its three constituents: Header, Payload, and Signature. It then attempts to verify the digital signature using the secret key you provide, ensuring data integrity.
Practical Usage
JWTs are the standard for stateless authentication in modern web apps. This debugger helps developers inspect token claims (like user ID, expiration, roles) and verify that the backend's signing process is working correctly.
Documentation
For the official JSON Web Token standard, refer to RFC 7519.
Key Facts about JWTs
- JWTs consist of three parts: Header, Payload, and Signature.
- The header usually specifies the signing algorithm (e.g., HS256).
- The payload contains claims like issuer, subject, and expiration.
- Verification ensures the token hasn't been tampered with.