Modern web applications rely heavily on token-based authentication, specifically JSON Web Tokens (JWT). When debugging login issues, session expirations, or authorization scopes, being able to quickly decode an auth token is crucial. Our JWT Decoder takes your base64Url encoded authentication token and instantly breaks it down into its three constituent parts: the Header (algorithm and token type), the Payload (claims, user data, expiration), and the Signature.
Because JWT payloads are simply encoded, not encrypted, anyone who intercepts the token can read the data. Our tool helps developers verify exactly what user information and scopes are being exposed in their tokens, ensuring no sensitive data like passwords are inadvertently included.