May 17, 2024

Choosing The Right OAuth Grant Types For Your User

Discover the ins and outs of OAuth grant types and learn how to implement secure, user-friendly authentication flows. This comprehensive guide covers the different OAuth grant types, their best use cases, and practical tips for customizing your authorization flow.

By Joel CoutinhoSoftware Developer at SuperTokens

Table of Contents

In today’s digital landscape, secure authentication and authorization are crucial for protecting user data and providing a seamless experience. OAuth 2.0, a widely adopted framework, facilitates this by allowing third-party applications to access user resources without exposing credentials. This blog aims to define OAuth grant types, their best use cases, and how to build a secure, user-friendly authorization flow. We will also highlight how SuperTokens can help you achieve these goals effortlessly.

What Is OAuth & OAuth Flow?

OAuth 2.0 is an authorization framework that enables applications to obtain limited access to user accounts on an HTTP service, such as Facebook, GitHub, or Google. It works by delegating user authentication to the service that hosts the user account and authorizing third-party applications to access the user account. This delegation is accomplished through a series of steps known as the OAuth flow.

The typical OAuth flow involves:

  1. Client Registration: The application registers with the authorization server to obtain a client ID and client secret.
  2. Authorization Request: The application requests authorization from the user.
  3. Authorization Grant: The user approves the request and provides an authorization grant.
  4. Access Token Request: The application exchanges the authorization grant for an access token.
  5. Access Token Response: The authorization server issues an access token.
  6. Resource Request: The application uses the access token to access the user’s resources.

What Are OAuth Grants?

OAuth grants are methods of obtaining an access token, which represents the authorization granted to the application to access the user’s resources. Each grant type serves a different purpose and has specific use cases. Understanding these types is essential for selecting the appropriate one for your application’s needs.

OAuth Grant Types & Use Cases

Authorization Code Grant

Use Case: Best for web and mobile applications where the client can securely store the client secret.

The Authorization Code Grant is the most common and secure OAuth grant type. It involves an intermediate authorization code, which the application exchanges for an access token. This process ensures that the client secret remains confidential and the access token is obtained securely.

Implicit Grant

Use Case: Suitable for single-page applications (SPAs) and other public clients that cannot securely store the client secret.

The Implicit Grant type allows the application to directly receive the access token in the redirect URL, bypassing the intermediate authorization code step. While faster, it’s less secure because the access token is exposed to the user agent and potential interception.

Client Credentials Grant

Use Case: Ideal for server-to-server interactions where no user involvement is necessary.

In the Client Credentials Grant type, the application directly uses its client credentials to obtain an access token. This is typically used for backend services or applications accessing resources on their own behalf rather than on behalf of a user.

Resource Owner Password Grant

Use Case: Suitable for trusted applications where the user can provide their username and password directly.

This grant type allows the application to obtain the access token by directly requesting the user’s credentials. It should be used sparingly due to security risks associated with handling user credentials directly.

Refresh Token Grant

Use Case: Ideal for long-lived access and applications that require access tokens to be refreshed periodically.

The Refresh Token Grant allows an application to obtain a new access token using a refresh token without involving the user again. This is useful for maintaining persistent access without repeatedly prompting the user for credentials.

What Is The Most Common Grant Type?

The Authorization Code Grant is the most common OAuth grant type due to its balance of security and usability. It is widely used in web and mobile applications where the client can securely store the client secret.

Is There A “Best Method” OAuth Grant Type?

There is no one-size-fits-all “best method” for OAuth grant types. The choice depends on the specific use case, application architecture, and security requirements. Each grant type has its strengths and is best suited for particular scenarios.

Which OAuth Grant Type Is The Most Secure?

The Authorization Code Grant is considered the most secure OAuth grant type. By using an intermediate authorization code and securely exchanging it for an access token, this grant type minimizes the risk of token interception and unauthorized access.

How To Customize Your Authorization Flow To Fit Your Security Needs Without Impacting Your User

Customizing your authorization flow involves balancing security requirements with user experience. Here are some best practices:

  1. Use Appropriate Grant Types: Select the OAuth grant type that best fits your application’s architecture and security needs.
  2. Implement PKCE (Proof Key for Code Exchange): For public clients, use PKCE to enhance the security of the Authorization Code Grant.
  3. Secure Storage of Tokens: Ensure access tokens and refresh tokens are securely stored and transmitted.
  4. Regular Token Rotation: Implement token rotation to minimize the impact of token compromise.
  5. Monitor and Audit: Continuously monitor and audit OAuth flows for potential security issues.

SuperTokens simplifies implementing secure and user-friendly authentication flows. By offering robust tools and detailed documentation, SuperTokens ensures you can build a customized, secure authorization flow without compromising user experience.


OAuth grant types provide a flexible framework for securing access to user resources in third-party applications. By choosing the right grant type and implementing best practices for security and user experience, developers can ensure robust authentication and authorization mechanisms. SuperTokens offers comprehensive tools and resources to simplify OAuth integration, making it easier to build secure and user-friendly applications.

For more in-depth comparisons and guides, check out our other blogs:

By understanding OAuth grant types and their use cases, you can make informed decisions that enhance both security and user experience. SuperTokens stands out by offering easy-to-implement, secure authentication solutions tailored to your needs.

Software dev and content lead at SuperTokens. Contributed to the SuperTokens core, backend SDKs, and developer documentation.