JWT vs. Bearer Token: What’s the Difference?

Bearer tokens and JSON Web Tokens (JWTs) are distinct yet complementary components in modern authentication systems, often misunderstood as interchangeable. Bearer tokens, defined in RFC 6750, function as an authentication scheme where possession of the token grants access, making them ideal for APIs due to their simplicity and stateless nature. JWTs, outlined in RFC 7519, serve as a token format that encapsulates user information in a self-contained, verifiable string, commonly used as bearer tokens due to their compactness and support across various platforms. While JWTs are preferred for stateless, scalable systems, opaque bearer tokens offer advantages in scenarios requiring immediate revocation and centralized session management. Understanding the distinction between bearer tokens as a transport method and JWTs as a data format is crucial for making informed architectural decisions, with the choice between JWTs and opaque tokens depending on specific needs such as performance, privacy, and real-time updates.