OAuth vs. JWT: What Is the Difference? Can You Use Them Together?

Authentication
What Is OAuth? What Is JWT? 
Open Authorization (OAuth) is an open standard for token-based authentication over public networks.
OAuth allows third-party services such as Facebook and Google to use end-user account information without exposing the user’s account credentials to a third party. 
It acts as an intermediary on behalf of end users, providing access tokens to third-party services authorized to share certain account information. The process of obtaining a token is called the authorization flow.
JSON Web Tokens (JWT) are an open industry standard for sharing information between two entities, typically a client (the front end of an application) and a server (the back end of an application).
A JWT contains a JSON object with information that needs to be shared. Additionally, each JWT is cryptographically signed, so that clients or malicious parties cannot modify JSON content (also known as JWT claims).

In this article:

OAuth vs. JWT: Pros and Cons 

OAuth Advantages

  • It is widely used. Most authentication services understand and use OAuth 2.0.
  • There are many plug-and-play OAuth solutions. For example, popular social networks support OAuth, making it easy to provide authentication options like “sign in with Google” or “sign in with Facebook”.
  • OAuth has well-tested client libraries in almost every language and web framework. This means that you can use OAuth with any programming language.
  • OAuth allows for code isolation, meaning client application code is not affected by the authorization code. OAuth is highly secure and field tested.

OAuth Disadvantages

  • Can be complicated to understand for beginners. There are several OAuth flows, and it can be difficult to decide which one is right for you. In some cases, you may need to use multiple processes.
  • OAuth might be too complex for some scenarios. For example, a simple application with one frontend and one backend probably does not require the OAuth protocol.
  • OAuth can create privacy concerns for end users, because the authentication server knows all sites the end user has logged into. For example, if a site uses Sign in with Google, Google can track when users on that site are signed in and active.

JWT Advantages

  • JWTs can transfer user details. This eliminates the need to query the database or authentication server for that information on every request.
  • JWTs can be verified efficiently and quickly, because they do not require a database lookup.
  • JWTs are only stored on the client side—the server generates a JWT and sends it to the client. The client then sends a JWT with each request. This saves database storage space.
  • JWTs provide strong security guarantees. They are digitally signed and cannot be modified by clients or attackers.

JWT Disadvantages

  • JWTs cannot be revoked without significant additional engineering work, because there are no database calls when validating.
  • Immediate revocation of JWT requires implementing a JWT blacklist, which can be time consuming.
  • If the signing key is compromised, an attacker can use it to construct a valid JWT. This makes it possible to impersonate the identity of a user.

When to Use JWT vs. OAuth 

Both protocols are widely used and supported, but they have different purposes and use cases.

JWT is a compact and self-contained way to transmit information between parties as a JSON object. It is often used to securely transmit information between parties, such as an API and a client application, or a server and a client application. JWTs are typically used to authenticate users and provide authorized access to resources, such as user data and files. JWT is suitable for stateless applications, as it allows the application to authenticate users and authorize access to resources without maintaining a session state on the server.

OAuth, on the other hand, maintains a session state on the server and uses a unique token to grant access to the user’s resources. It enables a user to grant a third-party application access to their resources on another site without giving away their username and password. OAuth is often used to allow a user to log in to a third-party application using their account on a different site, such as logging in to a music streaming service using your Google account. OAuth provides a secure way for the user to give permission for the third-party application to access their resources without exposing their login credentials.

To summarize:

  • Use cases – JWT is better suited to APIs. OAuth is useful for web, API, and browser applications and resources. 
  • Tokens – JWT defines the token format. OAuth defines the authorization protocols.
  • Usability – JWT is easier to learn and use from the initial stages. OAuth is more complex.
  • Storage – JWT can only use client-side storage. OAuth can use both server-side and client-side storage. 
  • Scope – JWT handles fewer use cases and has a smaller scope. OAuth is more flexible and easily used for various use cases.

Related content: Read our guide to OAuth flow

Using JWT with OAuth2 

Although JWT and OAuth2 serve different purposes, they are compatible and can be used together. Because the OAuth2 protocol does not specify a token format, JWT can be incorporated into OAuth2 usage.

For example, the access_token returned by the OAuth2 authorization server could be a JWT carrying additional information in the payload. This can improve performance by reducing the round trips required between the resource server and the authentication server. 

Another common way to use JWT with OAuth2 is to issue two tokens as access_token: a reference token and a JWT containing identity information in addition to the access token. However, for use cases that require this implementation, consider using OpenID Connect, an extension of OAuth2 that provides additional normalization by including access_token and id_token fields.

A common misconception is that using JWT with OAuth2 increases application security, but this is not necessarily true. Like any other standard, JWT is not an impenetrable mechanism. OAuth2 security is maintained by defining the actors involved in the authorization process and the specific steps to be taken for this process in various use cases. Security issues with OAuth2 are best addressed by choosing the right OAuth2 authorization flow for your application based on your use case, and not by token type.

The advantage of using JWT over OAuth2 is improved performance and reduced process complexity for some processes. However, it can also complicate development. A good starting point when deciding whether to use JWT with OAuth2 is to consider whether the increased performance is worth the extra development effort for your application.

Using OAuth and JWT with Frontegg

Frontegg’s end-to-end and self-served authentication infrastructure is based on JSON Web Tokens. Our JWTs have been designed to adhere to the highest security standards. Therefore, our user management solution is also fully compliant with the OAuth protocol, along with OpenID Connect 1.0 (OIDC) as well. We cover all important bases that are required in the modern SaaS space. 

Furthermore, Frontegg’s advanced authentication capabilities allow an easy and smooth integration between your SaaS app and other third-party solutions. You can do this by using the JSON Web Key Set (JWKS) endpoints on offer, along with the refresh tokens and public certificate that come with the JWT mechanism. This has made Frontegg a proven and tested development accelerator for better TTM.

That’s not all. With Frontegg’s user-friendly and intuitive offering, it takes just a few minutes along with some lines of code to make your SaaS app fully JWT protected. So what are you waiting for? Get onboard today.

Learn more about Frontegg