While both SAML and OIDC are most commonly used to implement single sign-on (SSO), there is a difference in their implementation approach. While SAML doesn’t pair well with some apps (e.g. mobile apps), OpenID works well with both web and mobile apps. SAML, however, is a protocol that has already appeared in 2005 and also due to this time it is a protocol many times more popular than OIDC.