Best Identity Providers With Enterprise SSO Support (2026)

ZITADEL is the most balanced choice for SaaS companies adding enterprise SSO for the first time. It's open-source under Apache 2.0 with a managed cloud option, and crucially, SAML 2.0 and OIDC are first-class features on every plan rather than being gated behind a sales call. The multi-tenant model is built around "organizations," which maps cleanly to the way B2B SaaS sells — each enterprise customer gets their own isolated org with its own IdP connections, branding, and admin policies.

The pricing is what makes ZITADEL stand out for this use case. Unlike Auth0 or Okta, you don't hit a paywall the moment a customer asks for SAML — the cloud's free tier supports SSO connections, and paid plans are priced per active user rather than per organization, which keeps costs predictable as you sign more enterprise accounts. For teams that want zero per-MAU cost, the self-hosted version offers the same feature set including SCIM 2.0, audit logs, and IdP-initiated login flows.

The trade-off is maturity: ZITADEL is younger than Okta or Auth0, the community is smaller, and you'll find fewer Stack Overflow answers when debugging tricky IdP configurations. The admin console is functional but not as polished as the established players. For teams comfortable with reading source code when needed, it's a strong fit.

Keycloak is the heavyweight open-source IAM platform, maintained by Red Hat and battle-tested at enterprises that authenticate hundreds of thousands of users. For SSO specifically, it's hard to beat: it speaks SAML 2.0, OIDC, and OAuth 2.0 fluently, brokers identity to upstream IdPs like Okta, Azure AD, and Google Workspace, and federates users from LDAP and Active Directory with minimal configuration. The realm-based multi-tenancy is well-suited to giving each enterprise customer their own isolated identity boundary.

Where Keycloak shines is total cost at scale. Once you're authenticating tens of thousands of users, hosted IdPs become eye-watering — Keycloak's $0 license keeps cost flat and predictable as MAUs grow. Identity brokering is particularly strong: you can sit Keycloak in front of your app and let it broker to any number of customer IdPs without your application needing to know SAML exists.

The honest downside is operational. Keycloak is a substantial Java application that wants real attention — upgrades have historically broken things, HA setup requires Infinispan tuning, and the documentation, while thorough, can feel like reading a spec rather than a guide. If your team doesn't have at least one engineer who enjoys running Java services in production, the TCO calculation tilts toward a hosted alternative.

Okta is the de facto enterprise identity standard — it's the IdP your customers most likely already run, which is exactly why so many SaaS teams also use Okta on the other side as their customer-facing identity provider (via Okta Customer Identity, formerly Auth0 by Okta). For SSO support specifically, Okta's strength is brand trust: when a Fortune 500 buyer sees "Okta" in your security documentation, they move past the SSO question instantly.

The platform supports every protocol that matters — SAML 2.0 with all the encrypted-assertion and IdP-initiated edge cases, OIDC with full discovery, SCIM 2.0 for provisioning, and rich audit logging that satisfies most SOC 2 and ISO 27001 auditors. The Universal Directory makes federating from upstream IdPs straightforward, and the policy engine handles complex enterprise requirements like step-up MFA for sensitive actions and IP-based access policies.

The catch is cost and complexity. Okta's pricing is opaque and very much enterprise-tier — you'll likely sign a six-figure annual contract once you have any real volume, and the per-feature pricing means SCIM, advanced MFA, and lifecycle management often cost extra. For a small SaaS landing its first three enterprise customers, Okta is overkill; for one serving Fortune 500 buyers who demand a known-brand IdP, it's the safest choice on the market.

Auth0 (now part of Okta) is the developer-friendly identity platform that built its reputation on excellent SDKs, a polished dashboard, and rules/actions that make extending auth logic feel like writing normal code. For enterprise SSO, Auth0 supports the full protocol stack — SAML 2.0, OIDC, and WS-Fed — plus SCIM, MFA, and a deep catalog of pre-built enterprise IdP connections including Okta, Azure AD, Google Workspace, Ping, and ADFS.

The big appeal for B2B SaaS is the Organizations feature, which models each enterprise customer as a separate tenant with its own SSO connections, branding, and member roles. Combined with the Universal Login experience and a real React/Next.js/Node SDK story, Auth0 is the fastest path to shipping enterprise SSO if you're already used to a developer-first auth flow.

The critical caveat: enterprise SSO and Organizations live on the B2B Essentials and Professional plans, which price per organization (per enterprise customer connection) rather than per MAU. The economics work well at a handful of enterprise customers but get expensive fast once you have 20+ orgs, and the published pricing has changed multiple times in recent years. Read the current pricing carefully before you commit — what looked affordable at the pilot stage can become a serious line item at 50 customers.

Ory takes a different architectural approach — instead of one monolithic IAM product, it ships a suite of composable open-source services: Kratos for identity and login, Hydra for OIDC/OAuth 2.0 provider, Keto for fine-grained authorization, and Oathkeeper for identity-aware proxying. For enterprise SSO, you typically combine Kratos (for the user-facing identity) with Hydra (to act as an OIDC provider) and brokering to upstream SAML/OIDC IdPs.

This composability is a real advantage if your engineering team likes Go-style microservices and wants each layer of auth to be replaceable. It's particularly compelling for product teams that need both customer identity and rich authorization (RBAC, ReBAC) because Ory Keto is one of the few mature open-source answers to Google Zanzibar-style permission systems. The Ory Network managed cloud lets you adopt the stack without running everything yourself.

The trade-off is that enterprise SSO with Ory is more assembly than out-of-the-box. SAML support specifically has historically lived in Ory's commercial Network/Enterprise offerings rather than the OSS components, so check the current SKU breakdown before committing if SAML is a hard requirement. The docs are good, but you're integrating several services rather than configuring one — expect a longer initial setup compared to ZITADEL or Auth0.

SuperTokens is the developer-first open-source authentication platform that's gained traction as a self-hostable alternative to Auth0. The core is Apache 2.0 licensed and includes session management, social login, passwordless, MFA, and a clean recipes-based SDK model that makes adding auth to a React/Next.js or Node app remarkably fast.

For enterprise SSO specifically, SuperTokens supports SAML 2.0 and OIDC via its multi-tenancy feature, which lets you configure per-tenant IdP connections for each enterprise customer. The self-hosted core is free, and the managed SuperTokens Cloud handles the operational side if you don't want to run the database and core service yourself. Per-MAU pricing on the cloud is significantly cheaper than Auth0 at comparable scale, which is the main reason teams pick it for B2B use cases.

The honest caveats: some enterprise features (SAML, multi-tenancy, SCIM-style provisioning) are part of the paid feature set rather than the fully free OSS core, so read the current pricing page carefully. The ecosystem of pre-built enterprise IdP guides is smaller than Auth0's — if you need turn-key Okta and Entra ID integrations with quick-start docs, you may end up writing more configuration yourself. Still, for cost-conscious teams that want a modern, developer-friendly auth platform with open-source escape hatches, it's a strong fit.