What is a JWT?

JSON Web Tokens (JWTs) are a secure way to transmit information between systems. They're commonly used for authentication—when you log into a website, you often receive a JWT that proves your identity for subsequent requests.

JWT Decoder

JWT Token

Header

Payload

Signature

What is a JWT?

Header: The algorithm and token type (usually HS256 or RS256).

Payload: The actual data—user ID, permissions, expiration time, and other claims.

Privacy First: Your tokens are decoded locally in your browser. They're never sent to any server.