The Ultimate JWT Debugging Guide for latest

JWT Security in the Modern Era

JSON Web Tokens (JWTs) are the backbone of modern stateless authentication. However, they are often misunderstood, leading to critical security vulnerabilities. ### The Anatomy of a JWT A JWT is not encrypted; it is merely Base64Url encoded. Anyone who has the token can see your payload. This is why you should never store sensitive data like passwords or PII inside a JWT. ### Common Debugging Scenarios 1. Expired Tokens (exp): The most common reason for 401 Unauthorized errors. Always check the 'exp' claim in our Secure JWT Decoder. 2. Malformed Signature: Occurs when the secret or public key used for signing doesn't match the one used for verification. 3. Invalid Audience (aud): If your token was intended for 'api-v1' but you're calling 'api-v2', the verification will fail. ### Why Local Decoding? When you use a cloud-based JWT tool, your session token is transmitted over the internet to their server. If that server is compromised, your session is compromised. DevUtility Hub performs all decoding in your browser's memory, ensuring your secrets stay on your machine.