12 Best FusionAuth Alternatives & Competitors (2026)

Auth0 is a cloud identity platform offering extensive social and enterprise connections plus MFA. Its hosted login pages simplify frontend work but introduce redirect flows and usage-based pricing that grows with active users. SuperTokens differentiates by letting teams self-host on their own infrastructure, avoid per-MAU fees, and keep full control over the authentication database and UI components while still providing comparable passwordless and SSO recipes.

Firebase Authentication provides quick social and email sign-in tightly coupled with Google Cloud services. It excels at mobile apps but can feel limiting for teams wanting full data ownership or complex multi-tenancy rules. SuperTokens runs independently of any cloud provider, supports custom password policies and session limits, and keeps all user data on infrastructure you control.

Auth0 is a cloud identity platform offering extensive social and enterprise connections plus MFA. Its hosted login pages simplify frontend work but introduce redirect flows and usage-based pricing that grows with active users. SuperTokens differentiates by letting teams self-host on their own infrastructure, avoid per-MAU fees, and keep full control over the authentication database and UI components while still providing comparable passwordless and SSO recipes.

Keycloak is a popular open-source identity server with strong SAML and OIDC support used by many enterprises. It requires managing multiple services and a steeper initial configuration curve. SuperTokens offers a lighter modular architecture, faster 5-minute setup, and tighter framework SDK integration for modern stacks like React and Node without the same operational overhead.

Permit.io provides a no-code policy editor and SDKs for ABAC and ReBAC. It emphasizes quick UI-based policy creation and integrates with many identity providers. Compared with AuthZed it offers simpler onboarding for non-engineers but lacks the same strong-consistency guarantees and AI-specific RAG tooling that AuthZed ships with SpiceDB.

Permit.io provides a no-code policy editor and SDKs for ABAC and ReBAC. It emphasizes quick UI-based policy creation and integrates with many identity providers. Compared with AuthZed it offers simpler onboarding for non-engineers but lacks the same strong-consistency guarantees and AI-specific RAG tooling that AuthZed ships with SpiceDB.

Cerbos is an open-source, self-hosted authorization engine focused on decoupled policy decisions over APIs. It excels in GitOps policy workflows and lightweight deployment. Versus AuthZed it provides full control and zero cloud dependency but requires more operational effort to reach the global scale and managed consistency AuthZed delivers out of the box.

Clerk focuses on developer-friendly React components and hosted authentication with strong prebuilt flows. While convenient, it relies on Clerk's cloud and usage pricing. SuperTokens gives the same prebuilt UI option plus complete self-hosting freedom, open-source transparency, and no mandatory redirects to third-party domains.

Okta delivers enterprise-grade identity with broad protocol support and governance features at premium pricing. It targets large organizations needing advanced workflows. SuperTokens serves startups and mid-market teams seeking similar SSO and multi-tenancy capabilities at lower cost through open-source self-hosting and simpler integration.

Ory Keto implements Google Zanzibar-style relationships as an open-source service within the Ory stack. It is strong for identity-centric use cases. AuthZed offers a more complete managed cloud experience, AI authorization examples, and higher-level features such as customer-managed permissions that Ory Keto leaves to additional integration work.

OPA is a general-purpose policy engine using Rego for any domain including Kubernetes and microservices. It is extremely flexible yet requires writing low-level policies. AuthZed abstracts common authorization patterns with a higher-level schema language and provides enterprise ReBAC features plus AI retrieval support that OPA does not target natively.