OAuth vs JWT for Authentication

When building applications that require user authentication, developers often get confused between OAuth and JWT (JSON Web Tokens). While both are related to authentication and authorization, they serve different purposes and can even be used together.

OAuth is a protocol that enables applications to obtain limited access to user accounts on other services. When you click ""Login with Google,"" you're using OAuth. The application gets a token to access specific parts of your Google account, but not your actual Google password.

JWT, on the other hand, is a format for securely transmitting information between parties as a JSON object. This token contains user information and is digitally signed to ensure it hasn't been tampered with. When a user logs in, the server creates a JWT containing user details and permissions, which the client then uses for subsequent requests.

OAuth involves multiple parties: the user, the application (client), and the authentication server (like Google). The application redirects users to the authentication server, where they log in directly. This makes OAuth more secure for third-party authentication since the application never sees the user's credentials.

JWTs are simpler - they typically involve just the application and its users. The application handles login directly and issues JWTs. While this is fine for simple applications, it means you're responsible for securely storing and managing user credentials.

Here's what makes each option better for different scenarios:

• Use OAuth when you want users to log in using their existing accounts from other services (like Google or Facebook)

• Use JWTs when you're building a self-contained application and want to manage authentication yourself

Here's a comparison of OAuth and JWT: