JWT Decoder
Decode and inspect JSON Web Tokens. Free, no signup.
How It Works
Paste a JWT token and click Decode. The header and payload are Base64-decoded and displayed as formatted JSON. The signature is shown but not verified (that requires the secret key). No data is ever sent to a server.
What Is a JWT?
A JSON Web Token (JWT) is a compact, URL-safe token used for authentication and information exchange. It consists of three Base64-encoded parts separated by dots: header (algorithm and type), payload (claims and data), and signature (verification). JWTs are widely used in OAuth, APIs, and single sign-on systems.