Authentication Protocols

OIDC vs. Oauth2: What’s the Difference?

OIDC and OAuth2 are two of the most common protocols in the realms of user management and security. Although the terms are often mentioned together, they differ regarding purposes and functionalities.

As many struggles to understand the difference between OIDC and OAuth2, this article aims to shine the light of clarity on the subject. This will help IT admins, developers, and businesses choose the best protocol.    

Difference between Authentication & Authorization

Authentication and authorization are two distinctive notions. Used interchangeably, they refer to distinguishable processes that serve different purposes.

Authentication verifies a user’s identity. This process involves verifying the identity of the user. The verification is typically performed via passwords, PIN, biometrics (fingerprint, facial recognition), 2FA, and MFA

On the other hand, Authorization focuses on granting/denying access to specific resources. Once a user’s identity has been verified, authorization determines their access level. Moreover, that further dictate what actions they can access within a system.

What’s OIDC

OpenID Connect (OIDC) is an identity protocol with a standardized format for exchanging authentication information between websites and authentication services.

OIDC leverages OAuth 2.0 and adds an identity layer to the authorization framework. The new layer enables websites and applications to authenticate users through other service providers. 

For instance, users can use their existing login credentials from an OIDC provider (such as Google). Then, they can access different applications and websites without the hassle of creating and remembering multiple passwords.

OIDC offers robust security measures by eliminating the risks of traditional passwords, which are prone to hacking and easy to guess. With OIDC, unique and unpredictable passkeys can be generated for each user, ensuring stronger security.

OpenID Connect excels in scalability and flexibility. From single-page applications to native and mobile apps, OIDC caters to diverse client types, making it suitable for various use cases. Additionally, it utilizes JSON Web Tokens (JWT) and HTTP flows, avoiding sharing user credentials with services and enhancing security.

What’s OAuth2

OAuth 2 focuses on authorizing access via an authentication server (like Facebook) to user resources to a client on behalf of its owner.

Using OAuth 2.0, resource owners can authorize third-party applications to access their personal data, such as contacts or profile information, through authentication and resource servers – without sharing their login credentials. 

OAuth 2.0’s authorization workflow is made possible through the issuance of access tokens by an authorization server. These tokens allow the client application to access protected resources hosted by the resource server.

Using OAuth2 eliminates the need for users to disclose their passwords to third-party services, reducing the risk of unauthorized access. New features like short-lived tokens and improved signatures make the technology more versatile and adaptable to various scenarios.

OAuth 2.0 is widely adopted as an industry standard thanks to the secure and efficient authorization mechanism. Also, it supports various client types, including web and mobile applications.

OIDC vs. OAauth 2 

Primary Focus

OIDC’s main focus is authentication, verifying a user’s identity to provide access to a service. Whereas OAuth 2 focuses on authorization, allowing clients to access user resources via third-party authorizers.

OpenID Connect features the following four parties:

  • Relying Party (RP): The client requesting a user’s identity.
  • OpenID Provider: The hub that performs user authentication, consent, and token issuance. Also, it provides a one-time code to RP.
  • Token Endpoint: Accepts the one-time code and provides a digitally-signed code via JWT that can be verified within an hour by RP. 
  • UserInfo Provider: Relying Party communicates with UserInfo Provider by providing the secure token to get access to user information. 

OAuth 2 features the following four parties:

  • Client: The app/service that’s requesting the protected resources.
  • Resource Owner: The user that owns the resources.
  • Resource Server: API that stores the user information like contacts, name, profile photo, etc. 
  • Authorization Server: OAuth’s main engine generates access tokens via services like Facebook, Google, etc. 

Token Types

Three types of tokens are available in OIDC: ID, Access, and Refresh. The ID token contains information about the user, like their unique identifier name, email address, name, etc. This token provides a standardized way to obtain user identity information without additional API calls.

With OAuth 2.0, you only get Access and Refresh tokens. The client uses the access tokens to access the protected resources of users. And the refresh tokens let the client obtain new access tokens without requiring additional user authentication. 

Process Flows

Here are the three process flows of OIDC:

  • Implicit: Tokens are directly given to RP through a re-direct – mainly used for single-page apps.
  • Authorization Code: Implemented where security is the utmost priority. Moreover, it can be used with JWT tokens for added safety.
  • Hybrid: The ID token is returned to RP via a re-direct, but the access token isn’t given. An authorization code is provided in exchange for an access token. 

The following are three process flows of OAuth 2.0:

  • Authorization Code: Works perfectly for mobile and web-based services.
  • Client Credentials: Provides access to the apps when the user isn’t present.
  • Password: Users log in by manually entering their credentials.  


OAuth 2.0 specifications are flexible, making it easy for developers to integrate them. However, making most implementations optional results in the rise of vague and bad practices. 

There’s also a lack of built-in security features in OAuth 2.0. It depends on developers to implement correct combinations for putting security measures in place—for instance, secure token storage and management.

On the other hand, OIDC comes with a set of security features. OpenID Connect incorporates standardized mechanisms for user authentication. This includes ID Tokens, verified identity claims, and more. 


OIDC uses claims to define the user information an app can access from the iDP (identity provider). Inside the claims, user attributes are defined like Email, Name, Profile Picture, and more.

OAuth2.0 uses scopes to define the permissions granted to the client service. Scopes contain information on actions and data that an app can use on the user’s behalf.   

Implementing OIDC Auth Using Vault Vision

Are you looking forward to integrating OIDC authentication into your website? We can help you out. At Vault Vision, we support OIDC Google, Apple, and Microsoft logins to accelerate your customers’ sign-in process. 

We are officially certified by OIDC to distribute their cutting-edge technology to apps & website owners worldwide. Furthermore, the integration is available on all major development environments like React, Node, Webflow, Python, Go, etc. Also, preconfigured setups, starter kits, and no-code apps make things super easy.   

Final Words

There’s a clear difference between OIDC and OAuth 2. The one is made for both user authentication & authorization, while the latter only works to authorize users. The other notable distinctions are token types, process flows, security, and scopes.

Our state-of-the-art authentication platform lets you speed up the authentication process by implementing OIDC. You can test out our Free, Launch, and Growth plans by registering yourself – no credit card details are required. 


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