Social authentication in 2025 has become essential for modern web applications, driven by the widespread adoption of social media, with Facebook leading at a 61% market share for social logins and a global user base of 5.42 billion. The security landscape has shifted significantly due to sophisticated OAuth 2.0 attacks, highlighting the necessity for robust security measures and seamless cross-platform user experiences. In response, the industry has introduced RFC 9700, which mandates PKCE for all OAuth clients, eliminates insecure flows, and requires exact string matching for redirect URIs to bolster security. Clerk has emerged as a leading solution for React/Next.js applications, offering rapid implementation with enterprise-grade security features, including automatic adoption of OAuth security best practices, SOC 2 Type 2 certification, and comprehensive documentation. As organizations navigate the complexities of balancing user experience, security, and compliance, the choice between managed services like Clerk or open-source solutions like NextAuth.js depends on technical requirements and scalability needs. Understanding and implementing OAuth 2.0 security best practices as outlined in RFC 9700 is crucial for protecting user trust and organizational reputation in the digital age.