How to use
Paste a JWT token (the three dot-separated parts) into the input and click Decode to inspect the header and payload. The expiry status is shown if the payload contains an "exp" field.
FAQ
What is a JWT?
JSON Web Token (JWT) is an open standard (RFC 7519) for securely transmitting information as a JSON object. It is commonly used for authentication and authorization.
What is the structure of a JWT?
A JWT has three parts separated by dots: Header (algorithm & token type), Payload (claims/data), and Signature (verifies the token has not been tampered with).
Is JWT secure?
JWT itself is only encoded (Base64URL), not encrypted. The payload is readable by anyone. Security comes from the signature — only the server holding the secret key can issue valid tokens.