UI/UX Best Practices for IdP & SP-Initiated SSO

This post discusses UI/UX best practices for IdP (Identity Provider) and SP (Service Provider) initiated Single Sign-On (SSO) flows, which are essential in modern web applications. It covers two unique flows - IdP-initiated SSO and SP-initiated SSO. The article provides examples of how various companies implement these flows, such as subdomaining tenants, separating email and password screens, and dynamically hiding password fields for domains with SSO enabled. While adding SSO doesn't eliminate the need for usernames and passwords entirely, it significantly improves the user experience by allowing users to sign in using their existing credentials from popular identity providers like Google or Twitter.