--- source_url: "https://clirank.dev/compare/auth-apis?utm_source=openai" title: "Best Auth API in 2026: Clerk vs Auth0 vs Supabase Auth vs Firebase Auth vs Better Auth | CLIRank" mirrored_at: 2026-08-15T15:04:34.492Z host: clirank.dev cited_in_42a: true mirror_canonical: "https://index.42a.ai/clirank.dev/compare/auth-apis__q__utm_source_openai" --- > **Original source:** https://clirank.dev/compare/auth-apis?utm_source=openai [Home](https://clirank.dev/)/[Compare](https://clirank.dev/compare)/Auth APIs Clerk vs Auth0 vs Supabase Auth vs Firebase Auth vs Better Auth Real MAU-based pricing, real setup times, working code. Last verified April 2026. TL;DR - **Fastest setup:** Clerk - 10 min, 8 lines, pre-built UI components - **Cheapest at scale:** Better Auth ($0 forever) or Supabase Auth ($25/mo for 100K MAU) - **Best enterprise SSO:** Auth0 - the gold standard for SAML/SSO/compliance - **Best for mobile:** Firebase Auth - Google ecosystem, Flutter/React Native first-class support - **Full control:** Better Auth - open source, self-hosted, zero vendor lock-in ## Pricing comparison (MAU-based) API Free tier 10K MAU 50K MAU 100K MAU [Clerk](https://clerk.com/) 10K MAU free Free $825 $1,825 [Auth0](https://auth0.com/) 25K MAU free Free $240 Custom [Supabase Auth](https://supabase.com/auth) 50K MAU free Free Free $25 [Firebase Auth](https://firebase.google.com/docs/auth) 50K MAU free Free Free $275 [Better Auth](https://www.better-auth.com/) Free forever (OSS)Pick Free FreePick FreePick ## Setup complexity API Time to working auth Lines of code Credit card? Pre-built UI? Clerk 10 minPick 8 linesPick No Yes Auth0 20 min 15 lines No Yes Supabase Auth 15 min 12 lines No Yes Firebase Auth 15 min 14 lines No Yes Better Auth 20 min 18 lines No No ## Feature comparison API Social login MFA SSO/SAML Self-hosted Magic links Clerk Yes Yes Yes No Yes Auth0 Yes Yes Yes No Yes Supabase Auth Yes Yes Yes Yes Yes Firebase Auth Yes Yes Yes No Yes Better Auth Yes Yes No Yes Yes ## Quickstart code Working TypeScript examples. Copy, set your env vars, authenticate. ## Which should you pick? ### You want the fastest setup **Clerk.** 10 minutes, 8 lines of code, pre-built UI components. Drop-in sign-in/sign-up that looks good out of the box. Purpose-built for Next.js and React. ### You want the lowest cost at scale **Better Auth.** $0 forever - it's open source. You pay for hosting only. If you want managed, Supabase Auth is $25/mo for 100K MAU. Both destroy Clerk on cost. ### You need enterprise SSO/SAML **Auth0.** The gold standard for enterprise identity. SAML, LDAP, Active Directory, compliance certifications. If your customers demand SSO, this is where you go. ### You're building mobile-first **Firebase Auth.** First-class Flutter and React Native support. 50K MAU free, Google Sign-In works out of the box. The natural choice if you're already in the Google ecosystem. ### You want open-source with Postgres **Supabase Auth.** Auth tied directly to your Postgres database with row-level security. 50K MAU free on the managed platform. Can self-host the entire stack. ### You want full control, self-hosted **Better Auth.** Framework-agnostic, runs anywhere, zero vendor lock-in. You own the code, the data, and the infrastructure. More setup work but total freedom. ## Get a personalised recommendation CLIRank's decision engine picks the best API for your specific volume, budget, and priorities. Works via API or MCP server - your agent can call it directly. `curl "https://clirank.dev/api/recommend?task=authenticate+users&volume=50000&priority=cost"` Or install the MCP server: `npx clirank-mcp-server@latest` ## Frequently asked questions ### Which auth API is cheapest at scale? Better Auth is free forever since it's open source - you only pay for your own hosting. For managed services, Supabase Auth costs just $25/month for 100K MAU. Firebase Auth costs $275/month at that volume. Clerk is the most expensive at $1,825/month for 100K MAU. ### Which auth API has the fastest setup? Clerk - 10 minutes to working auth with just 8 lines of code. Pre-built UI components mean you don't need to design sign-in forms. Supabase Auth and Firebase Auth both take around 15 minutes. ### Can I self-host any of these? Yes. Better Auth is fully open source and designed for self-hosting. Supabase Auth can also be self-hosted since the entire Supabase stack is open source. Clerk, Auth0, and Firebase Auth are cloud-only managed services. ### Which supports SSO/SAML? Auth0 is the strongest for enterprise SSO/SAML - it's their bread and butter. Clerk, Supabase Auth, and Firebase Auth all support SSO/SAML too. Better Auth does not natively support SAML. ### Which is best for Next.js? Clerk is purpose-built for Next.js with first-class App Router support, middleware helpers, and pre-built React components. Supabase Auth and Better Auth also integrate well but require more manual setup. Auth0 works fine with Next.js but is more oriented toward enterprise use cases.