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
Run the same test for every candidate
- Record the current workload, scale, integrations, access rules and recovery target.
- Import representative data and reproduce one critical end-to-end workflow.
- Force an integration failure, restore from backup and test a complete export.
- Measure operator time, infrastructure, license assumptions and support needs.
- Score every candidate against the published criteria and keep rollback evidence.
Test the change before committing
Migration and rollback
Inventory data, configuration, identities and integrations. Time a representative export, import and rollback before choosing a cutover plan.
Security and operations
Compare access controls, audit logs, update ownership, backup recovery, observability and the work required during an incident.
Total cost
Model licenses, infrastructure, data transfer, support and operator time at production scale. Record plan limits and renewal assumptions.
Technical shortlist
Clerk
A managed authentication platform oriented toward application developers and prebuilt user-management workflows.
Limits to confirm
- Confirm data location, export and exit terms because self-hosting is not recorded.
- Test API coverage, authentication, rate limits and failure handling.
- Review license, renewal and portability terms because an open-source license is not recorded.
FusionAuth
An identity platform with hosted and self-managed deployment options to evaluate for protocol and data-control requirements.
Limits to confirm
- Self-hosting shifts upgrades, backups and incident response to your team.
- Test API coverage, authentication, rate limits and failure handling.
- Review license, renewal and portability terms because an open-source license is not recorded.
SuperTokens
An open-source, self-hostable authentication option for teams that want application-level control and SDK integration.
Limits to confirm
- Self-hosting shifts upgrades, backups and incident response to your team.
- Test API coverage, authentication, rate limits and failure handling.
- Confirm the exact license and support boundary for deployed components.
Ory
A modular identity stack for teams prepared to compose authentication, authorization and related services.
Limits to confirm
- Self-hosting shifts upgrades, backups and incident response to your team.
- Test API coverage, authentication, rate limits and failure handling.
- Confirm the exact license and support boundary for deployed components.
WorkOS
A managed option to evaluate when enterprise SSO, directory integrations and B2B application requirements drive the project.
Limits to confirm
- Confirm data location, export and exit terms because self-hosting is not recorded.
- Test API coverage, authentication, rate limits and failure handling.
- Review license, renewal and portability terms because an open-source license is not recorded.
Official sources and directory fields checked on . Recheck current release notes, prices and plan limits before procurement.
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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