SAML vs OIDC vs OAuth 2.0: 12 Differences Every B2B Engineering Team Should Know

OAuth 2.0, OpenID Connect (OIDC), and SAML 2.0 are three distinct protocols used in enterprise authentication and authorization, each designed to address different needs. OAuth 2.0 serves as a framework for delegated authorization, allowing an application to access resources on behalf of a user without sharing the user's password. OIDC is built on top of OAuth 2.0 to provide user authentication by adding an ID Token, thus enhancing OAuth with identity verification capabilities. SAML 2.0, an older protocol ratified in 2005, is a browser-driven, XML-based standard primarily used for enterprise Single Sign-On (SSO) and federation. These protocols are not interchangeable, as they were developed by different standards bodies for distinct purposes, leading to significant differences in their operations. A B2B SaaS product typically supports all three protocols to meet the diverse requirements of enterprise customers. The article also discusses factors like the token formats, transport assumptions, session management, and the complexities involved in migration and security, offering insights into when to build in-house solutions versus opting for a broker like SSOJet, which handles protocol integrations efficiently and reduces engineering overhead.