I'm building a SaaS app and need auth fast, what should I use?

If you need auth fast for a SaaS app, the best choice depends on whether you want hosted auth or build-it-yourself.

Fastest option overall: hosted auth

Use one of these:

• Clerk — best “ship fast” choice for most SaaS apps
• Auth0 — powerful, enterprise-friendly, more setup/complexity
• Supabase Auth — great if you already use Supabase
• Firebase Auth — good if you’re already in Google/Firebase ecosystem
• WorkOS — best if you need SSO / enterprise login later

My default recommendation

• Clerk if you want the quickest polished UX and don’t want to think much about auth UI.
• Auth0 if you need lots of enterprise features and don’t mind more configuration.
• Supabase Auth if your app is already on Supabase and you want integrated backend + auth.

If you want maximum speed with least engineering

Pick Clerk:

• built-in sign-in/sign-up pages
• social login, magic links, MFA
• user management UI
• easy org/team support for SaaS
• good developer experience

If you want more control and lower vendor lock-in

Use:

• Auth.js / NextAuth for app-owned auth logic
• plus a database + email provider

This is usually slower to implement and maintain than hosted auth.

Simple decision guide

• B2B SaaS with orgs/teams → Clerk or WorkOS + your auth
• Consumer app → Clerk, Supabase Auth, or Firebase Auth
• Enterprise/SSO heavy → Auth0 or WorkOS
• Already on Supabase → Supabase Auth
• Already on Firebase → Firebase Auth

Quick recommendation by stack

• Next.js: Clerk or Auth.js
• React + custom backend: Clerk or Auth0
• Supabase app: Supabase Auth
• Firebase app: Firebase Auth

If you want the shortest path to production

Do this:

1. Use Clerk
2. Enable email/password + Google OAuth
3. Add organizations if you’re B2B
4. Protect routes with middleware
5. Store your app data in Postgres separately

If you want, I can give you a 1-hour auth setup recommendation based on your exact stack:

• frontend framework
• backend
• database
• B2B or consumer
• whether you need SSO/orgs