The JWT Debugger is a Firefox extension designed for developers working with JSON Web Tokens (JWTs). It integrates functionalities from the JWT.io website directly into the browser, providing features such as support for various JWT algorithms including HMAC, RSA, and ECDSA. The extension allows users to debug JWTs visually, making it easier to manage and troubleshoot token-related issues.

Recent updates have introduced enhancements such as stricter key checking and support for additional algorithms, ensuring that developers can work with the latest standards. Users can easily edit JWTs stored in cookies or web storage and generate shareable URLs for their tokens. The tool is aimed at streamlining JWT debugging processes, making it an essential addition for web developers focused on secure authentication.