OAuth2 vs OpenID – What’s The Difference (Explained)

Oauth2 vs OpenID – What’s The Difference. There are multiple ways to keep the data safe like there is many ways to attack your data. These options range from multi factor authentication to single sign on or on premises firewalls. Developers and IT professionals have to make wise choices in selecting a standard that can be deployed in keeping federated identities safe. However, this decision is not always straightforward. They thoroughly struggle to differentiate between Oauth2 and OpenID that has the ability to structure the federation process.

Both Oauth2 and OpenID are HTTP based protocols that developers or IT professionals use for authentication or authorization. While authentication allows entry to the system, authorization helps them to access particular features within those systems.

This blog talks about Oauth2 vs OpenID and what these two standards mean and what are their  difference. 

What Is Oauth2?

Oauth2, also known as Open Authorization protocol is a standard that is designed for a website or application. It enables them to access resources hosted by other web apps in support of another user.

It is the latest version of Oauth and is now an existing industry standard for online authorization. It sanctions access and restricts actions that a client app is able to perform on resources on behalf of the user. All these actions are done without sharing the user’s credentials.

The specification of Oauth2 protocol describes the techniques to handle delegated access to other client types such as browser based applications, server side web applications, connected devices, native/mobile apps, and many more.

How Does OAuth2 Work?

OAuth only authorizes devices, APIs, servers with access tokens are preferred over credentials as it works better than HTTP. Before using Oauth2, the client must get the credentials (client ID and client secret from the Authorization Server). All these things are required for identifying and authenticating itself while it requests an Access Token.

With the help of Oauth2, the client has to initiate the access request. Then, the token request, exchange, and response will proceed in the following general flow:

  • The client requests authorization to supply client Id and secret from the Authentication Server to and as identification.
  • It also provides scopes and end point URI for sending Access Token or Authorization code.
  • Next the Authorization server substantiates the client and verifies that the request scopes are permitted.
  • The Resource owners also interact with the Authorization Server to accept access.
  • Depending upon the type of grant, the Authorization Server redirects back to the Client with the help of an Authentication code or Access Token.
  • With the help of an Access Token, the client now requests a Resource server to grant access to the resources.

What Is OpenID?

OpenID Connect or OIDC is an identity protocol which task is to authorize and authenticate  of OAuth 2.0. The user can use an existing account and use multiple websites without the need for creating passwords. You only have to associate with your OpenID to share the name and the email address with the websites you visit. OpenID enables you to control the information you are sharing with these websites.

Also, the password you acquire with the help of OpenID is only given to your identity provider that confirms your identity to the website you visit. Therefore, it eliminates you from being worried about an unsculptured and insecure website that wants to use your identity.

With OpenID identity protocol it may also be used for Single Sign On (SSO) across applications. OpenID has a consent built in and it is a powerful alternative to somehow more complex SAML 2.0.

How Does OpenID Work?

An OpenID Connect includes three parties:

  • the client,
  • the end user
  • the identity provider.


The client, also known as the Relying Party sends the end user to the identity provider. Here the end user authenticates the identity and authorizes access to the client. Then, the client receives an authorization code from the identity provider that is used for requesting access and ID tokens from the identity provider. After receiving the token, the client is allowed to perform an action on behalf of the end user.

OpenID uses a signed and cryptographical JSON web token, which is verified to ensure that the access and the identity token have not interfered while exchanging the information between the parties.

Oauth2 vs OpenID – What’s The Difference?

Oauth2 vs OpenID

Oauth2 framework is about granting authorization. The application which uses Oauth establishes a request for permissions to a third party system (Identity Provider). This Identity Provider manages the Authentication process and returns an Access Token as successful. The identity provider requires additional factors like SMS or email. With Oauth2 the content and structure of the Access Token remained undefined by default. 

OpenID or OIDC is an identity layer on top of OAuth2.0.It is like an extension that adds and defines an ID token for returning a user’s information. The id token is a JWT and contain information about the authenticated user. The identity provider signs it. When signed in with help of the Identity Provider it returns particular fields that are expected and handled by your applications. It is significant to know that OpenID is not a replacement for Oauth2. It is a special and simplified case of it instead. It utilizes similar terminology and concepts.

Scope & Access Control

Scope or permission is how you define and apply fine grained access control of individual resources, information or actions available to the system.

In OpenID, the scopes are defined as Openid, profile, email, address and phone. All these grants are accessible to specific information. 

Oauth does not define naming conventions, relationships or access for specific scopes. Practically, different systems adapt the meaning of admin scope differently. While positively it means that a company like Google can create highly structured and predictable Oauth scopes, whereas negatively it means Github has scopes like a user, read: user, and user: email to provide read only access to the user profile.

Claims Management

The claim means the name or value pair fixed within our Access or ID Token. Oauth2 specifications do not have the concept of claims. Hence, it enables the user to define the code the way they want. However, it possess a challenge to enable people to define themselves however they want to. Later, the JWT specification introduces the concept and defines a basic structure. But, it did not set any conventions for names, structure, etc.

OpenID protects you from such conventions. It defines the straightforward set of claims for its users’ details like name, address, etc. Therefore, when the user only uses these claims and restricts access according to proper scopes, they will be familiar with the information they are sharing and the know how of the application they are currently using.

No matter whatever standard they use, they will achieve user authentication and deploy single sign on respectively.

Also, Oauth2 enables the user to access the login page or a new pop up page whenever they want to. On the other hand, OpenID helps them to log in to a third party app simply by entering OpenID credentials to the 3rd party applications.

Oauth2 vs OpenID – What’s The Difference Conclusion

One of the simplest examples to understand the difference between OpenID Connect and OAuth2.0

With OpenID Connect you Sign in with third party provider Google, Facebook or  LinkedIn or your own identity server (like Azure AD). 

But with OAuth2.0 is like a consent that you/owner will give to the client app and authorizing the app to access protected resources.

OpenID Connect can work as a proxy for other protocols like SAML

You should always remember that these two authorization concepts should be deployed according to the needs of the enterprise. A sturdy identity solution uses these structures to achieve different ends. The selection entirely depends upon the type of operations from which an organization needs to protect itself.

Both Oauth2 and OpenID bring efficiency to the security of various native and web apps. Hence, cybersecurity or IT professionals should be knowledgeable enough to protect their web or native applications using these API integrations. It can be achieved by signing in authentication or authorization protocols.

Avatar for Hitesh Jethva
Hitesh Jethva

I am a fan of open source technology and have more than 10 years of experience working with Linux and Open Source technologies. I am one of the Linux technical writers for Cloud Infrastructure Services.

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