This article was originally published on AI Study Room . For the full version with working code examples and related articles, visit the original post. Best Authentication Solutions 2026: Clerk vs Auth0 vs Supabase Auth vs NextAuth vs Lucia Authentication is the last thing you should build from scratch. Clerk, Auth0, Supabase Auth, NextAuth, and Lucia take different approaches to the same problem: getting users logged in securely without 100 hours of work. Here's the comparison. Quick Comparison Clerk Auth0 Supabase Auth NextAuth (Auth.js) Lucia Type Hosted + embeddable UI Hosted (universal login) Hosted (Supabase platform) Library (bring your own DB) Best for React/Next.js, best DX Enterprise, multi-protocol Supabase users, simplicity Full control, open source Free tier 10K MAU, unlimited projects 7.5K MAU (B2C), 500 (B2B) 50K MAU Free (open source) Social login Google, GitHub, Apple, 20+ more 40+ providers Google, GitHub, Apple, 10+ 50+ providers (configure yourself) Multi-tenancy Excellent (organizations…