Best self-hosted customer identity platforms
3 models · updated 2026-08-04
The verdict
Keycloak leads — All 3 models rank Keycloak the top pick.
As of 2026-08-04, ChatGPT, Claude and Gemini collectively rank Keycloak #1 for self-hosted customer identity platforms on ModelsAgree — unanimous among the 3 models that have answered. The models' case: The best all-round value: mature, fully open-source, highly extensible, and unusually broad across OIDC, OAuth, SAML, federation, organizations, passkeys, authorization. The models' main caveat: Production customization and multi-cluster operation demand substantial identity and platform expertise. The strongest alternative is ZITADEL — Near-tied with Keycloak and arguably better for greenfield B2B SaaS: first-class organizations and projects, strong delegated administration. Source: https://modelsagree.com/best/best-self-hosted-customer-identity-platforms (modelsagree.com, CC BY 4.0).
Combined ranking
- 1GPT #1Claude #1Gemini #1
The best all-round value: mature, fully open-source, highly extensible, and unusually broad across OIDC, OAuth, SAML, federation, organizations, passkeys, authorization, and deployment patterns. It narrowly beats ZITADEL when protocol breadth, longevity, and avoiding feature licenses matter most.
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GPT The best all-round value: mature, fully open-source, highly extensible, and unusually broad across OIDC, OAuth, SAML, federation, organizations, passkeys, authorization, and deployment patterns. It narrowly beats ZITADEL when protocol breadth, longevity, and avoiding feature licenses matter most.
Claude The mature, battle-tested standard for self-hosting — full OIDC/OAuth2/SAML, identity brokering, social login, fine-grained authz, and a vast community with abundant tutorials, operators, and Kubernetes tooling; Red Hat backing means it isn't going anywhere and it costs nothing.
Gemini Battle-tested open-source benchmark for enterprise CIAM offering complete protocol support (OIDC, OAuth2, SAML 2.0), robust user federation, fine-grained access control, and deep Java SPI customization. Ranked top under the assumption that long-term protocol stability and zero-vendor-lock-in outweigh setup complexity for typical enterprise deployments.
Where it falls shortper GPT Production customization and multi-cluster operation demand substantial identity and platform expertise; SCIM remains preview-grade.
per Claude Heavy JVM footprint and operationally complex to run reliably at scale; its lineage is workforce/enterprise IAM, so consumer-scale UX customization and high-volume tuning take real effort, and the admin experience feels dated.
per Gemini High memory footprint and a steep administration learning curve make simple app integrations unnecessarily over-engineered for lean teams.
- 2GPT #2Claude #2Gemini #3
Near-tied with Keycloak and arguably better for greenfield B2B SaaS: first-class organizations and projects, strong delegated administration, API-first automation, passkeys, SAML/OIDC, SCIM, and comprehensive audit events in a comparatively efficient package.
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GPT Near-tied with Keycloak and arguably better for greenfield B2B SaaS: first-class organizations and projects, strong delegated administration, API-first automation, passkeys, SAML/OIDC, SCIM, and comprehensive audit events in a comparatively efficient package.
Claude Purpose-built modern CIAM — multi-tenancy, event-sourced audit trail by design, strong B2B/organization modeling, passkeys/FIDO2 first-class, clean APIs and good DX; a genuinely current architecture rather than a retrofitted legacy one.
Gemini Modern Go-based, cloud-native identity platform offering first-class multi-tenancy, native Passkeys/WebAuthn support, built-in immutable audit logs, and lightweight resource usage out of the box.
Where it falls shortper GPT Its smaller ecosystem and more opinionated architecture make unusual integrations, troubleshooting, and migrations riskier than with Keycloak.
per Claude Younger ecosystem and smaller community than Keycloak; the event-sourcing + Postgres/CockroachDB storage model adds operational learning curve, and you'll hit fewer prewritten answers when troubleshooting.
per Gemini Younger project ecosystem with significantly fewer third-party integrations and smaller community documentation compared to established industry giants.
- 3GPT #3Claude #3Gemini #2
Purpose-built for customer identity with native multi-tenancy, flexible user data schemas, high-throughput performance, and webhooks designed for custom registration flows. Shares a near-tie with Keycloak for teams prioritizing rapid developer onboarding over pure open-source licensing.
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Gemini Purpose-built for customer identity with native multi-tenancy, flexible user data schemas, high-throughput performance, and webhooks designed for custom registration flows. Shares a near-tie with Keycloak for teams prioritizing rapid developer onboarding over pure open-source licensing.
GPT A polished, purpose-built CIAM server with straightforward self-hosting, strong APIs and documentation, flexible theming, real tenant isolation, broad login methods, and good migration tooling; typically faster to operationalize than Keycloak.
Claude The most CIAM-focused of the bunch with a polished admin console, excellent documentation, generous self-host tier, and thoughtful consumer features (themes, MFA, lambdas, per-application tenanting) that make it fast to ship a real product.
Where it falls shortper GPT It is proprietary open-core software, and capabilities such as SCIM, advanced threat detection, tenant administration, and parts of WebAuthn require licenses.
per Claude Source-available, not truly open source, and single-vendor — several advanced features sit behind paid editions, so you're accepting lock-in and a licensing ceiling.
per Gemini Advanced enterprise capabilities like multi-region database sync, advanced SAML, and dedicated support require paid commercial licenses despite the free self-hosted edition.
- 4GPT #5Claude #4Gemini #5
API-first, headless, cloud-native building blocks that give maximum flexibility and clean separation of concerns; ideal when you want to own the UI entirely and compose exactly the flows and authz model you need at scale.
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Claude API-first, headless, cloud-native building blocks that give maximum flexibility and clean separation of concerns; ideal when you want to own the UI entirely and compose exactly the flows and authz model you need at scale.
GPT Its Kratos and Hydra stack offers exceptional headless flexibility, strong standards foundations, customizable identity schemas and flows, passkeys/MFA, and proven OAuth/OIDC scalability; it is ideal when the identity experience must be deeply product-specific.
Gemini Headless, API-only identity management providing strict security isolation, zero UI opinions for complete frontend design freedom, and high-performance Go microservice deployment.
Where it falls shortper GPT It is a toolkit rather than a turnkey CIAM: teams must assemble services, build or adapt user interfaces, and own considerably more integration and operations work.
per Claude Not a turnkey product — no bundled login UI and multiple services to wire together, so it demands significant engineering investment and is overkill for teams wanting something that works out of the box.
per Gemini Offers no out-of-the-box user interfaces, creating high initial developer overhead to build and maintain all login, registration, and account recovery screens.
- 5GPT #4Claude —Gemini —
The most approachable modern option for product teams, with excellent hosted-login UX, clean SDKs and management APIs, organizations, organization RBAC, enterprise SSO, MFA, passkeys, and simple PostgreSQL-based deployment.
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GPT The most approachable modern option for product teams, with excellent hosted-login UX, clean SDKs and management APIs, organizations, organization RBAC, enterprise SSO, MFA, passkeys, and simple PostgreSQL-based deployment.
Where it falls shortper GPT The self-hosted edition has commercial restrictions, including a three-SAML-app limit, and its ecosystem and operational track record remain narrower than the leaders’.
- 6GPT —Claude —Gemini #4
Developer-first architecture delivering pre-built UI components and modular backend SDKs that embed directly into web and mobile codebases, giving teams complete control over user data with minimal setup overhead.
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Gemini Developer-first architecture delivering pre-built UI components and modular backend SDKs that embed directly into web and mobile codebases, giving teams complete control over user data with minimal setup overhead.
Where it falls shortper Gemini Focuses tightly on modern web/mobile authentication and session management, lacking built-in support for legacy enterprise SAML federation without third-party bridges.
- 7GPT —Claude #5Gemini —
Modern, approachable UX with a powerful flow/stage engine, broad protocol support, and a fast-improving open-source project that self-hosters genuinely enjoy operating.
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Claude Modern, approachable UX with a powerful flow/stage engine, broad protocol support, and a fast-improving open-source project that self-hosters genuinely enjoy operating.
Where it falls shortper Claude Its center of gravity is workforce SSO/application access rather than high-volume consumer identity, some enterprise features are paid, and it's backed by a comparatively small team.
By use case
How this board's leaders rank when the same four models are asked a more specific question.
| Product | This board | auth platform | multi-tenant B2B SaaS | OAuth and OpenID Connect server |
|---|---|---|---|---|
| Keycloak | #1 | #1 | #7 | #1 |
| ZITADEL | #2 | #2 | #9 | #2 |
| FusionAuth | #3 | #5 | — | #6 |
| Ory | #4 | #4 | — | — |
| Logto | #5 | #7 | — | — |
| SuperTokens | #6 | #8 | #8 | — |
| Authentik | #7 | #3 | — | — |
Just missed the top 5
GPT SuperTokens — excellent embedded authentication and session management, but important CIAM capabilities such as multi-tenancy, MFA, and unified OAuth-provider behavior are paid and its SDK-centric architecture is less broadly interoperable · authentik — strong self-hosted SSO and application-access platform, but its center of gravity remains workforce and homelab access rather than customer-facing B2B organization workflows
Claude Logto — excellent developer-first modern CIAM and strong for startups, but younger with a smaller ecosystem and less proven at large scale · Supabase Auth / GoTrue — great value when you're already in the Supabase/Postgres stack, but thin as a standalone, protocol-complete CIAM outside that ecosystem
Gemini Authentik — engineered primarily for internal workforce SSO and IT infrastructure access control rather than customer-facing application registration and user flows · Logto — provides an impressive Auth0-like developer experience, but has a less mature track record for complex enterprise multi-tenant customizations
By model
ChatGPT
- 1.Keycloak
- 2.ZITADEL
- 3.FusionAuth
- 4.Logto
- 5.Ory
Claude
- 1.Keycloak
- 2.ZITADEL
- 3.FusionAuth
- 4.Ory
- 5.Authentik
Gemini
- 1.Keycloak
- 2.FusionAuth
- 3.ZITADEL
- 4.SuperTokens
- 5.Ory
Common questions
What is the best self-hosted customer identity platforms according to AI models?
Keycloak leads. All 3 models rank Keycloak the top pick. The current top 3: Keycloak, ZITADEL, FusionAuth. Ranked by asking ChatGPT, Claude, Gemini the same buying question and merging their top-5 picks, updated 2026-08-04. Source: modelsagree.com.
Which self-hosted customer identity platforms did each AI model pick first?
ChatGPT: Keycloak. Claude: Keycloak. Gemini: Keycloak.
How is this self-hosted customer identity platforms ranking made?
ChatGPT, Claude, Gemini are each asked the same buying question in a fresh session with no system steering. Their top-5 answers are merged (rank 1 = 5 pts … rank 5 = 1 pt) into the consensus ranking, re-polled on demand and tracked over time.
More on how polling works: full methodology →
Cite this ranking
ModelsAgree, “Best self-hosted customer identity platforms” — merged ranking from ChatGPT, Claude, Gemini & Grok, polled 2026-08-04. https://modelsagree.com/best/best-self-hosted-customer-identity-platforms (CC BY 4.0)
Tracked by ModelsAgree · rank 1 = 5 pts … rank 5 = 1 pt · re-polled on demand