I'm building a SaaS app and need the fastest way to add SSO support. What should I use?

If your goal is the fastest way to add SSO to a SaaS app, the usual best choice is a managed identity platform rather than building SAML/OIDC handling yourself.

Best fast options

• Auth0 — very quick to integrate, broad SSO support, good docs, common choice for SaaS.
• WorkOS — especially strong if you want enterprise SSO + directory sync (SCIM) with a simpler SaaS-focused API.
• Clerk / FusionAuth / Okta — also options, depending on how much you want to own vs outsource.

What I’d recommend

• Use WorkOS if you’re specifically adding B2B SaaS enterprise SSO and want the fastest path to:
  • SAML + OIDC SSO
  • SCIM provisioning
  • enterprise-ready features without a lot of plumbing
• Use Auth0 if you want a more general-purpose auth platform and expect broader consumer + enterprise auth needs.

Fastest implementation path

1. Add your app’s login with OIDC/SAML via the provider
2. Let customers configure their IdP (Okta, Azure AD, Google Workspace, etc.)
3. Map the returned identity to your internal user/org model
4. Add org-level enforcement for SSO

Important note

If you mean “support SSO for enterprise customers”, don’t build SAML directly unless you have to — it’s slower and more error-prone than using a provider.

If you want, I can also give you:

• a recommendation by stack (Next.js, React, Rails, Django, etc.), or
• a feature-by-feature comparison of Auth0 vs WorkOS vs Clerk.