JWT Decoder

Decode JSON Web Tokens (JWT) instantly to view their header and payload claims securely.

Encoded JWT

Header (Algorithm & Type)

Payload (Data)

What is a JSON Web Token (JWT)?

JSON Web Tokens are an open, industry standard (RFC 7519) method for representing claims securely between two parties. JWTs are commonly used for Authentication and Information Exchange in modern web applications.

Our JWT Decoder allows developers to quickly inspect the contents of a JWT without needing to send it to a backend server. This tool safely decodes the Base64Url encoded segments (Header and Payload) directly within your browser to protect your sensitive tokens.

Understanding JWT Structure

Header: Typically consists of two parts: the type of the token, which is JWT, and the signing algorithm being used, such as HMAC SHA256 or RSA.
Payload: Contains the claims. Claims are statements about an entity (typically, the user) and additional data.
Signature: Used to verify the message wasn't changed along the way. Note: This tool decodes the data but does not verify the cryptographic signature.