ClerkIdentity & Access ManagementClerk provides pre-built authentication UI, session management and user management for developers, via SDKs for React, Next.js and other frameworks, with a free Hobby tier and paid Pro/Business plans.
APIfreemium
Other options to evaluate
Alternatives to Auth0
Authentication is application infrastructure. Before replacing Auth0, inventory every login flow, tenant, identity provider, token audience, machine client and administrative dependency that must continue to work.
Migration starts with requirements
Before changing tools
Separate authentication, authorization, directory synchronization and workforce SSO requirements. Test account migration, session revocation and signing-key rotation before comparing developer experience.
OIDC, OAuth, SAML, SCIM and MFA coverageHosted versus self-hosted operating modelSDK, API and framework integrationTenant migration, audit logs and recovery
Use the profile fields below as a starting point, then confirm current capabilities, migration paths, licensing and pricing in the official documentation.
ClerkIdentity & Access Management
FusionAuthIdentity & Access ManagementFusionAuth is a downloadable CIAM server with a free, unlimited-user Community edition, offering OAuth2/OIDC/SAML, MFA and passwordless login for any language or stack.
Self-hostedAPIfreemium
SuperTokensIdentity & Access ManagementSuperTokens provides open-source, self-hostable authentication — email/password, social login, passwordless, MFA, session management, and RBAC — plus a managed cloud service that's free up to 5,000 monthly active users and usage-priced beyond that.
Open sourceSelf-hostedAPIopen source
OryIdentity & Access ManagementOry builds open-source identity infrastructure — Kratos (identity/auth), Hydra (OAuth2/OIDC), Keto (permissions), and Oathkeeper (API gateway) — plus Ory Network, a managed cloud service with a free developer tier and paid production plans from $770/year.
Open sourceSelf-hostedAPIopen source
WorkOSIdentity & Access ManagementWorkOS provides APIs for enterprise-readiness features, SSO, SCIM directory sync, audit logs and RBAC, that SaaS companies embed to sell into large enterprise customers, with a free tier up to 1M monthly active users via AuthKit.
APIfreemium
Technical shortlist
Clerk
A managed authentication platform oriented toward application developers and prebuilt user-management workflows.
FusionAuth
An identity platform with hosted and self-managed deployment options to evaluate for protocol and data-control requirements.
SuperTokens
An open-source, self-hostable authentication option for teams that want application-level control and SDK integration.
Ory
A modular identity stack for teams prepared to compose authentication, authorization and related services.
WorkOS
A managed option to evaluate when enterprise SSO, directory integrations and B2B application requirements drive the project.
Keep the current option in the proof of concept
A replacement decision should use the same workloads, failure tests and cost assumptions for every candidate.
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