Top Auth0 Alternatives in 2026: Open Source and Managed Options

Last updated: March 2026

The strongest Auth0 alternatives in 2026 are Keycloak (self-hosted or managed via Skycloak), FusionAuth, SuperTokens, Ory, and Zitadel for teams that need open-source or self-hostable options, and Clerk for frontend-first teams that want prebuilt UI components. Keycloak is the most complete replacement: it covers OIDC, SAML 2.0, LDAP/AD federation, SCIM, fine-grained authorization, and custom authentication flows — everything Auth0 charges enterprise pricing for — with no per-MAU charges.

This guide compares all six alternatives on pricing, features, and trade-offs so you can pick the right fit for your team.

Why Teams Leave Auth0

Before diving into alternatives, it helps to understand the common reasons teams start looking elsewhere:

• Pricing at scale. Auth0 charges per monthly active user (MAU). Once you pass the free tier, costs climb quickly. Enterprise features like Organizations, custom domains, and advanced MFA require higher plans.
• Okta acquisition concerns. Since Okta acquired Auth0 in 2021, some teams worry about product direction, support quality, and long-term pricing changes.
• Customization limits. Auth0 Actions replaced Rules and Hooks, but deep customization of login flows, consent screens, and user federation still requires workarounds.
• Data residency. Teams with strict compliance requirements sometimes need full control over where user data lives.

If any of these resonate, the alternatives below offer different trade-offs worth evaluating. For a deeper head-to-head breakdown, see our Keycloak vs Auth0 comparison guide.

The Alternatives at a Glance

Provider	Type	Open Source	Pricing Model	Best For
Keycloak (Skycloak)	Self-hosted / Managed	Yes (Apache 2.0)	Free + hosting costs	Teams wanting full control with optional managed hosting
FusionAuth	Self-hosted / Cloud	Community Edition (free)	Per-MAU (cloud) or free (self-hosted)	Mid-market teams needing enterprise features
SuperTokens	Self-hosted / Managed	Yes (Apache 2.0)	Free (self-hosted) / Per-MAU (managed)	Startups wanting a lightweight, developer-first auth layer
Clerk	SaaS only	No	Per-MAU	Frontend-heavy apps needing prebuilt UI components
Ory	Self-hosted / Cloud	Yes (Apache 2.0)	Per-MAU (cloud) or free (self-hosted)	API-first teams comfortable with headless auth
Zitadel	Self-hosted / Cloud	Yes (Apache 2.0)	Free tier + per-MAU	Teams wanting a modern, cloud-native alternative

1. Keycloak with Skycloak Managed Hosting

Keycloak is the most widely deployed open-source identity and access management platform. Maintained by Red Hat and backed by a large community, it supports OIDC, SAML 2.0, OAuth 2.0, and LDAP/Active Directory federation out of the box.

Why it stands out as an Auth0 alternative:

Keycloak gives you the full feature set that Auth0 charges enterprise prices for, including single sign-on, multi-factor authentication, identity brokering, RBAC, custom authentication flows, and fine-grained authorization. Because it is open source, there is no per-MAU pricing ceiling.

The main trade-off has historically been operational overhead. Running Keycloak in production means managing infrastructure, upgrades, backups, and high availability. This is where Skycloak’s managed hosting eliminates the pain. You get the full power of Keycloak without managing the infrastructure yourself.

Key features:

• Full OIDC, SAML 2.0, and OAuth 2.0 support
• Identity brokering with any OIDC or SAML provider
• SCIM 2.0 provisioning for automated user lifecycle management
• Audit logging and session management
• Custom authentication flows and SPI extensions
• Multi-tenancy via realms and the Organizations feature
• Custom branding for login pages and emails
• WebAuthn/passkey support for passwordless authentication

Pricing:

• Keycloak itself: free and open source
• Self-hosted: infrastructure costs only (typically $50-300/month for a production-grade cluster)
• Skycloak managed: starts at predictable monthly pricing with no per-MAU charges. See pricing details

Pros:

• No vendor lock-in; your data and configuration are fully portable
• Most complete feature set of any open-source IAM platform
• Massive community and ecosystem (extensions, themes, integrations)
• No per-user pricing means costs stay predictable at scale
• SOC 2 certified managed hosting available through Skycloak

Cons:

• Self-hosted Keycloak requires DevOps expertise
• Admin console UI is functional but not as polished as some SaaS products
• Learning curve is steeper than simpler auth libraries

Best for: Teams that need enterprise-grade IAM without enterprise pricing. Ideal if you want full control over authentication flows, need SAML support, or are scaling past Auth0’s pricing thresholds.

To estimate how much you could save by switching, try our IAM ROI Calculator.

2. FusionAuth

FusionAuth positions itself as a developer-focused auth platform that can run anywhere. It offers a Community Edition that is free to self-host (though not open-source in the traditional sense; the source is available but the license is restrictive) and a paid cloud offering.

Key features:

• OIDC and SAML support
• Multi-tenancy with separate tenant configurations
• Breached password detection
• Advanced registration forms
• Entity management for non-user identity objects
• Connectors for LDAP and external data sources

Pricing:

• Community Edition: free to self-host (limited features)
• Starter plan: starts around $125/month
• Essentials and Enterprise: custom pricing based on MAU and features
• Features like advanced MFA, SCIM, and application-level themes require paid plans

Pros:

• Fast to get started with good documentation
• Self-hosted option available at no cost
• Flexible tenant isolation

Cons:

• Community Edition is missing key features (SCIM, advanced MFA, breached password detection)
• Not truly open source; source-available with a restrictive license
• Smaller community compared to Keycloak
• Cloud pricing can approach Auth0 levels at scale

Best for: Mid-market teams that want a self-hosted option with a more polished developer experience than raw Keycloak, and who do not need SAML identity brokering on the free tier.

For a detailed comparison, see our post on Keycloak identity brokering with FusionAuth.

3. SuperTokens

SuperTokens is an open-source authentication solution designed for simplicity. It focuses on core auth flows (email/password, passwordless, social login) and provides prebuilt UI components and backend SDKs.

Key features:

• Email/password, passwordless, and social login
• Session management with anti-CSRF protection
• Prebuilt React and vanilla JS UI components
• Multi-tenancy support
• User roles and permissions

Pricing:

• Self-hosted: free and open source (Apache 2.0)
• Managed service: free up to 5,000 MAUs, then per-MAU pricing
• Paid features include multi-tenancy, account linking, and MFA on the managed tier

Pros:

• Genuinely open source with a permissive license
• Very lightweight; easy to integrate into existing backends
• Good React/Next.js integration
• Active development pace

Cons:

• No SAML support (OIDC only)
• No identity brokering or federation capabilities comparable to Keycloak
• Limited enterprise features (no fine-grained authorization, limited audit logging)
• Smaller ecosystem and community

Best for: Startups and small teams building consumer-facing apps that only need OIDC-based authentication and want something lighter than a full IAM platform.

4. Clerk

Clerk is a SaaS-only authentication platform focused on frontend developer experience. It provides drop-in React components, Next.js integration, and a polished user management dashboard.

Key features:

• Prebuilt UI components (sign-in, sign-up, user profile)
• Next.js, React, and Remix SDKs
• Multi-session and multi-organization support
• User impersonation
• Bot detection and device management

Pricing:

• Free: up to 10,000 MAUs (limited features)
• Pro: $25/month + $0.02 per MAU beyond 10,000
• Enterprise: custom pricing
• Features like custom session durations, allowlists/blocklists, and SAML require Pro or Enterprise

Pros:

• Fastest time-to-integration for React/Next.js apps
• Beautiful prebuilt UI components
• Good documentation with framework-specific guides

Cons:

• SaaS only; no self-hosted option
• No SAML IdP capabilities
• Limited customization of authentication flows
• Vendor lock-in; migrating away means rebuilding auth entirely
• No standards-based federation (cannot act as an OIDC provider to downstream apps)

Best for: Small teams building Next.js or React apps that prioritize speed of integration over flexibility, and who do not need SAML or advanced IAM features.

5. Ory

Ory takes a modular, API-first approach to identity. The open-source stack consists of separate components: Kratos (identity management), Hydra (OAuth 2.0/OIDC server), Oathkeeper (API gateway), and Keto (authorization).

Key features:

• Headless, API-first architecture
• OAuth 2.0 and OIDC server (Hydra)
• Passwordless and WebAuthn support
• Relationship-based access control (Keto, inspired by Google Zanzibar)
• Self-service account management flows

Pricing:

• Self-hosted: free and open source (Apache 2.0)
• Ory Network (managed): free developer tier, then usage-based pricing
• Enterprise pricing for dedicated instances and SLAs

Pros:

• Truly modular; use only the components you need
• Strong OAuth 2.0 / OIDC compliance
• Zanzibar-style authorization is powerful for complex permission models
• API-first design works well in microservice architectures

Cons:

• No admin UI for the self-hosted version; everything is API/CLI-driven
• Steeper learning curve than most alternatives
• SAML support is limited
• Running the full stack (Kratos + Hydra + Oathkeeper + Keto) adds operational complexity
• Community is growing but smaller than Keycloak’s

Best for: Teams with strong backend engineering capabilities that want a headless, API-first identity layer and are comfortable without an admin GUI.

6. Zitadel

Zitadel is a newer entrant positioning itself as a cloud-native identity management platform. Written in Go, it emphasizes multi-tenancy and modern deployment patterns.

Key features:

• OIDC and SAML support
• Built-in multi-tenancy with organizations and projects
• Passwordless authentication with passkeys
• Actions (similar to Auth0 Actions) for customizing flows
• Self-service user management portal
• Branding customization per organization

Pricing:

• Self-hosted: free and open source (Apache 2.0)
• Cloud free tier: up to 25,000 authenticated requests
• Cloud Pro: usage-based pricing
• Enterprise: custom pricing with SLA

Pros:

• Modern architecture built for cloud-native deployments
• Good multi-tenant design from the ground up
• Active development and responsive team
• Supports both OIDC and SAML

Cons:

• Younger project with a smaller production track record
• Fewer third-party integrations and extensions compared to Keycloak
• Documentation is improving but has gaps
• Community is still growing

Best for: Teams looking for a modern, cloud-native identity platform that offers multi-tenancy as a first-class feature and are comfortable adopting a newer project.

Feature Comparison Matrix

Feature	Keycloak / Skycloak	FusionAuth	SuperTokens	Clerk	Ory	Zitadel
OIDC Provider	Yes	Yes	Yes	Limited	Yes	Yes
SAML 2.0 IdP	Yes	Yes	No	No	Limited	Yes
SAML 2.0 SP (Brokering)	Yes	Paid	No	No	No	Yes
Identity Brokering	Yes	Limited	No	No	Yes (Hydra)	Yes
MFA / 2FA	Yes	Yes (paid advanced)	Yes (paid managed)	Yes	Yes	Yes
WebAuthn / Passkeys	Yes	Yes	No	Yes	Yes	Yes
SCIM Provisioning	Yes	Paid	No	No	No	Limited
Fine-grained Authorization	Yes	No	No	No	Yes (Keto)	Limited
Custom Auth Flows	Yes (SPI)	Limited	Limited	No	Yes (Actions)	Yes (Actions)
Multi-tenancy	Yes (Realms/Orgs)	Yes	Yes (paid)	Yes (Orgs)	Yes	Yes
Admin Console	Yes	Yes	Dashboard	Dashboard	No (API only)	Yes
Self-hosted Option	Yes	Yes	Yes	No	Yes	Yes
Open Source License	Apache 2.0	Source-available	Apache 2.0	Proprietary	Apache 2.0	Apache 2.0

How to Choose

The right alternative depends on your specific requirements:

Choose Keycloak (with Skycloak managed hosting) if:

• You need the most complete feature set (OIDC + SAML + SCIM + brokering)
• Cost predictability at scale matters
• You want full control without vendor lock-in
• Compliance requirements demand data residency control
• You need to support workforce and customer identity in one platform

Choose FusionAuth if:

• You want a polished self-hosted product with commercial support
• You are primarily OIDC-focused and do not need heavy SAML brokering
• You are comfortable with feature-gated pricing

Choose SuperTokens if:

• You need lightweight auth for a consumer-facing app
• SAML and federation are not requirements
• You want something easy to embed into an existing backend

Choose Clerk if:

• You are building a Next.js or React app and want the fastest integration
• You do not need SAML, federation, or standards-based interoperability
• You are comfortable with SaaS-only and vendor lock-in

Choose Ory if:

• You want an API-first, headless identity stack
• Your team is comfortable without an admin GUI
• You need Zanzibar-style authorization

Choose Zitadel if:

• You want a modern, cloud-native platform with strong multi-tenancy
• You are comfortable adopting a newer project with a growing ecosystem

Migration Considerations

If you are currently on Auth0, migration involves several steps regardless of which alternative you choose:

1. User export. Auth0 allows exporting users via the Management API, but password hashes require special handling. Keycloak supports importing bcrypt-hashed passwords natively, which simplifies this step.

2. Client/application mapping. Each Auth0 application maps to a client in Keycloak (or equivalent in other platforms). Redirect URIs, grant types, and scopes need to be recreated.

3. Social connections. You will need to reconfigure each social identity provider (Google, GitHub, etc.) in the new platform with new OAuth credentials pointing to the new callback URLs.

4. Custom logic. Auth0 Actions and Rules need to be rewritten. In Keycloak, these map to custom authentication flows, protocol mappers, and event listeners.

For a detailed walkthrough, see our step-by-step Auth0 to Keycloak migration guide.

Frequently asked questions

What are the best open-source Auth0 alternatives?

The leading open-source Auth0 alternatives are Keycloak (Apache 2.0), SuperTokens (Apache 2.0), Ory (Apache 2.0), and Zitadel (Apache 2.0). Keycloak is the most feature-complete, supporting OIDC, SAML 2.0, LDAP/AD federation, SCIM, and fine-grained authorization in a single platform. SuperTokens and Ory are lighter and more modular but lack SAML and enterprise federation features. Zitadel is a newer option with strong multi-tenancy.

Is Keycloak a good Auth0 replacement for SAML support?

Yes. Keycloak supports SAML 2.0 both as an Identity Provider and as a Service Provider (for brokering with upstream SAML IdPs), making it a complete replacement for Auth0 in enterprise environments. Auth0 includes SAML only on its higher tiers, while Keycloak’s SAML support is built in and free regardless of user count.

How does Auth0 pricing compare to Keycloak at scale?

Auth0 charges per monthly active user, with costs escalating significantly on enterprise tiers that include custom domains, organizations, and advanced MFA. Keycloak is free and open source. Self-hosted infrastructure costs are typically $50–300 per month for a production cluster. Skycloak managed hosting uses flat-rate pricing with no per-MAU charges. The break-even point against Auth0 paid plans is typically in the low thousands of monthly active users.

Can you migrate password hashes from Auth0 to Keycloak?

Auth0 can provide bcrypt password hashes for database connection users upon request from their Support team. Keycloak natively supports importing bcrypt-hashed credentials via the Admin REST API, so users migrated this way can log in immediately without a password reset. For a detailed walkthrough, see the Auth0 to Keycloak migration guide.

Wrapping Up

The Auth0 alternatives landscape in 2026 is mature and competitive. For teams that need a full-featured IAM platform without per-user pricing constraints, Keycloak remains the strongest option, especially when paired with managed hosting that eliminates operational overhead.

The key questions to ask yourself are: Do you need SAML support? Is vendor lock-in acceptable? How important is cost predictability at 100K+ users? Your answers will naturally point toward the right solution.

If you are also evaluating Supabase alongside Keycloak — common when building a Postgres-backed application — see our full comparison in Supabase or Keycloak: a complete guide. For a deeper look at why teams choose Skycloak’s managed Keycloak over other providers, see why Skycloak is a premier choice in the IAM industry.

Ready to evaluate Keycloak as your Auth0 replacement? Try Skycloak free or explore our hosting plans to see how managed Keycloak compares to your current Auth0 bill. You can also use our ROI Calculator to estimate potential savings.