Top 8 Open-Source CIAM Platforms

Commercial CIAM platforms price by monthly active user, and that model turns a growing consumer base into a fast-growing bill. Open-source customer identity and access management offers an alternative: own the login, avoid per-user fees, keep customer data under your control, and audit the code that authenticates your users. For teams with the engineering capacity to run them, open-source CIAM can deliver registration, social sign-on, passwordless, and session management at infrastructure cost rather than per-MAU pricing.

CIAM has requirements that general identity tools do not always meet: frictionless sign-up, social and passwordless login, progressive profiling, consent capture, and the scale to handle millions of consumer accounts. This guide evaluates the eight open-source CIAM platforms worth knowing in 2026, with an honest read on where each fits and where it stops. For the commercial field, see the best CIAM platforms ranking, and for the general open-source identity landscape, our top open-source IAM solutions.

Evaluation Criteria

We assessed each platform against the following dimensions:

• Protocol support, OIDC, OAuth 2.0, SAML, and token standards
• Consumer login, social sign-on, passwordless, passkeys, magic links
• Multi-tenancy, organizations, B2B tenants, and isolation
• Developer experience, SDKs, APIs, hosted vs embedded UI, docs
• Scale, performance and architecture for high customer volumes
• Consent and privacy, consent capture and data-residency control
• Deployment, self-hosting complexity, Docker, Kubernetes, HA
• Community and support, activity, release cadence, commercial options

The Top 8 Open-Source CIAM Platforms

1. Keycloak

Best For: Teams wanting a full-featured, standards-complete identity provider they can bend to CIAM.

Overview

Keycloak is the most widely deployed open-source identity platform, and it serves customer identity well at moderate scale. It provides social login, user self-registration and self-service, identity brokering, and support for OIDC, SAML 2.0, and OAuth 2.0 out of the box, under the Apache 2.0 license. For CIAM specifically it needs tuning of its database and Infinispan caching at high volumes, and it lacks some consumer features like built-in consent and progressive profiling, but its breadth, maturity, and community make it the safe default for teams that want one platform for both customer and internal identity.

Key Features

• Social and enterprise identity brokering with 20+ providers
• User self-registration, self-service, and account console
• Full OIDC, OAuth 2.0, and SAML 2.0 support
• Themeable login flows and customizable authentication
• Admin REST API and fine-grained authorization services

License Apache 2.0. Free to self-host; Red Hat build of Keycloak is a paid subscription.

Pros

• Most feature-complete and battle-tested option here
• Huge community, documentation, and integration ecosystem
• Handles both workforce and customer identity

Cons

• High-scale CIAM requires careful database and cache tuning
• No built-in consent or progressive profiling
• Customization often requires Java expertise

---

2. Ory (Kratos, Hydra)

Best For: Engineering teams building custom, API-first identity into modern applications.

Overview

Ory takes an API-first, headless approach: Ory Kratos handles identity and user management, Ory Hydra is a certified OAuth 2.0 and OIDC provider, and Ory Keto handles permissions. There is no prescribed UI, so teams build their own login and registration against clean APIs, which suits product teams that want full control over the customer experience. Ory is cloud-native, scales horizontally, and is a strong fit for high-volume consumer apps, though the headless model means more work up front than a platform that ships a login UI.

Key Features

• Headless, API-first identity, OAuth 2.0, and permissions
• Certified OpenID Connect provider (Ory Hydra)
• Passwordless, MFA, and social sign-on flows
• Cloud-native, horizontally scalable architecture
• Ory Network managed cloud for teams that prefer hosted

License Apache 2.0. Free to self-host; Ory Network is a paid managed service.

Pros

• Total control over the customer login experience
• Cleanly separated, composable identity services
• Scales well for high-volume consumer apps

Cons

• You build the UI and glue; more up-front work
• Multiple services to operate and reason about
• Less turnkey than platforms with a hosted login

---

3. Zitadel

Best For: Multi-tenant SaaS that needs organizations and B2B identity out of the box.

Overview

Zitadel is a modern open-source identity platform built around multi-tenancy, with first-class support for organizations, making it a strong fit for B2B and B2B2C SaaS. It ships passwordless and passkey support, a management API, and an event-sourced architecture, and it offers both self-hosting and a managed cloud. Written in Go and designed for horizontal scale, Zitadel is one of the easier modern platforms to operate while still covering the multi-tenant needs that Keycloak handles less natively.

Key Features

• First-class organizations and multi-tenancy
• Passwordless and passkey (WebAuthn) support built in
• OIDC, OAuth 2.0, and SAML support
• Event-sourced architecture with a full audit trail
• Management API and actions for custom logic

License Apache 2.0. Free to self-host; Zitadel Cloud is a paid managed service.

Pros

• Multi-tenancy and organizations without extra plumbing
• Modern passkey and passwordless support out of the box
• Easier to operate than many alternatives

Cons

• Smaller ecosystem than Keycloak
• Fewer prebuilt enterprise integrations
• Younger project, though maturing quickly

---

4. Authentik

Best For: Self-hosting teams wanting a polished platform for customer and internal login.

Overview

Authentik is a modern open-source identity provider with a strong admin UI and a flexible flow builder for designing authentication and enrollment. It supports OIDC, SAML, and social providers, handles self-service registration and recovery, and is popular in self-hosted environments for both application SSO and lighter CIAM use cases. Its visual flow designer makes customizing sign-up and login approachable without deep coding, though at very large consumer scale it is less proven than Keycloak or Ory.

Key Features

• Visual flow builder for authentication and enrollment
• OIDC, SAML, and social sign-on support
• Self-service registration, recovery, and MFA
• Polished admin interface
• Outpost model for proxying access to applications

License Free open-source core; some enterprise features under a paid license.

Pros

• Approachable flow customization without heavy code
• Clean admin experience
• Good fit for mixed SSO and CIAM self-hosting

Cons

• Less proven at very high consumer scale
• Smaller community than Keycloak
• Some enterprise features are paid

---

5. SuperTokens

Best For: Developer teams that want to embed login into an app with a clean SDK.

Overview

SuperTokens is an open-source authentication platform focused on developer experience, with prebuilt UI components and SDKs that drop into a web or mobile app. It handles email and password, passwordless, social login, session management, and multi-tenancy, and it can be self-hosted for full data control or used as a managed service. SuperTokens is a strong fit for teams that want to own authentication without building it from primitives, though it is more focused on the login layer than on the broader governance and consent features of a full CIAM suite.

Key Features

• Prebuilt login UI components and SDKs
• Email/password, passwordless, and social sign-on
• Secure session management with rotating refresh tokens
• Multi-tenancy support
• Self-hosted or managed deployment

License Apache 2.0 core. Free to self-host; managed and some features are paid.

Pros

• Excellent developer experience and fast integration
• Self-host for full data control
• Strong, secure session handling

Cons

• Focused on login, lighter on governance and consent
• Smaller ecosystem than the largest platforms
• Some features gated behind paid tiers

---

6. FusionAuth (Community)

Best For: Teams wanting a complete CIAM feature set in one self-hosted download.

Overview

FusionAuth ships a broad CIAM feature set, registration, login, social sign-on, MFA, and user management, as a single downloadable application, and its Community edition is free to self-host with no user cap. It is developer-friendly with strong APIs and documentation, supports multi-tenancy and localization, and is a common choice for companies with strict data-residency requirements that need to run CIAM on their own infrastructure. Some advanced features and support are reserved for paid editions, but the free tier covers a lot.

Key Features

• Complete CIAM in a single self-hostable application
• Registration, login, social, and MFA out of the box
• Multi-tenant and multi-application support
• Strong APIs, webhooks, and localization
• No user cap on the free Community edition

License Community edition free; paid editions add advanced features and support.

Pros

• Turnkey CIAM without stitching services together
• Self-hostable for data residency
• Generous free tier with no user cap

Cons

• Source-available Community edition rather than a permissive OSI license
• Advanced features and SLAs require paid editions
• Single application to scale and operate

---

7. Logto

Best For: Startups building consumer or B2B apps that want a modern, affordable identity layer.

Overview

Logto is a modern open-source CIAM platform aimed at developers, with prebuilt sign-in experiences, passwordless and social login, organizations for B2B, and a clean console. It is designed to be quick to adopt, with SDKs across popular frameworks and a hosted option alongside self-hosting. Logto is younger than the established platforms, so validate high-scale and enterprise needs, but for startups that want a good-looking login and B2B multi-tenancy without a large bill, it is compelling.

Key Features

• Prebuilt, customizable sign-in experience
• Passwordless, social, and passkey support
• Organizations and roles for B2B multi-tenancy
• SDKs across popular web and mobile frameworks
• Self-hosted or Logto Cloud

License MPL-2.0 core (true open source); Logto Cloud is a paid managed service.

Pros

• Fast to adopt with a polished default experience
• B2B organizations built in
• Genuinely open-source license

Cons

• Younger and less proven at enterprise scale
• Smaller community and integration set
• Some features stronger in the managed cloud

---

8. Supabase Auth

Best For: Teams already building on Supabase that want authentication in the same stack.

Overview

Supabase Auth is the authentication component of the open-source Supabase platform, built on the GoTrue server. It provides email and password, magic links, social sign-on, and phone auth, tightly integrated with Supabase's Postgres database and row-level security, so authorization can be enforced at the data layer. For teams already on Supabase it is the path of least resistance, and it is fully self-hostable, though as an auth layer within a broader backend platform it is lighter on standalone CIAM features like consent and advanced multi-tenancy.

Key Features

• Email/password, magic link, phone, and social sign-on
• Tight integration with Supabase Postgres and row-level security
• JWT-based sessions that flow into database policies
• Self-hostable as part of the Supabase stack
• Simple client SDKs

License Apache 2.0 (GoTrue). Free to self-host; Supabase Cloud is paid.

Pros

• Frictionless if you already run Supabase
• Authorization enforced at the database layer
• Fully open-source and self-hostable

Cons

• Best value assumes the broader Supabase stack
• Lighter on standalone CIAM features
• Not designed as a standalone enterprise IdP

---

How to Choose

For a full-featured general identity provider that also covers customer identity, Keycloak remains the safe default. For modern multi-tenant SaaS, Zitadel gives you organizations out of the box and Ory gives you a headless, API-first foundation to build on. For developer-built consumer apps that want a clean SDK and a good-looking login, SuperTokens and Logto are the fastest to adopt, FusionAuth Community packs the most into one self-hosted download, and Supabase Auth is the natural choice if you already run Supabase.

As always with open source, the deciding factor is operational: CIAM runs on the critical path of every customer login, so a platform you cannot scale and keep patched is a liability. If your team lacks the capacity to run one at your customer volume, a managed option from the best CIAM platforms ranking may be the more honest choice. Compare specific pairs, such as Clerk vs Auth0, in our comparisons.