Encoded Token
Decoded Output
Header
{}Payload
{}Signature
Security & Privacy First: All decoding is performed securely in your browser using JavaScript. Your token is never sent to our servers.
What is a JSON Web Token (JWT)?
A JWT is a compact, URL-safe standard for creating access tokens that assert some number of claims. A token is composed of three parts, separated by dots (`.`):
- Header: Contains metadata about the token, such as the signing algorithm (e.g.,
alg: "HS256") and token type (typ: "JWT"). - Payload: Contains the claims, which are statements about an entity (typically, the user) and additional data. Common claims include
sub(subject),iss(issuer), andexp(expiration time). - Signature: A cryptographic signature used to verify that the sender of the JWT is who it says it is and to ensure that the message wasn't changed along the way.