JWT Token Generator

A JSON Web Token (JWT) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three parts: a header (algorithm & token type), a payload (claims), and a signature. JWTs are widely used for authentication and authorization in web applications.

This tool supports HMAC-based algorithms: HS256 (HMAC-SHA256), HS384 (HMAC-SHA384), and HS512 (HMAC-SHA512). These are symmetric signing algorithms that use a shared secret key for both signing and verification.

Yes — all signing happens locally in your browser using the Web Crypto API. Your secret key and payload data never leave your device. However, never use JWTs generated with a weak or publicly-shared secret in production.

Standard claims include: iss (issuer), sub (subject), aud (audience), exp (expiration time), iat (issued at), nbf (not before), and jti (JWT ID). You can also add any custom claims relevant to your application.