Authentik vs Keycloak: Self-hosted IdP comparison

SS. B. WriterMay 28, 20268 min read
Authentik vs Keycloak: Self-hosted IdP comparison

Authentik and Keycloak are self-hosted identity providers that help teams centralize login, single sign-on, multi-factor authentication, and protocol-based access across applications.

The useful comparison is not whether one has MFA and the other does not. Both support MFA and SSO. The useful comparison is scope, operating model, legacy integration, and how each handles the boundary between authentication and authorization.

This guide compares Authentik and Keycloak side by side, then shows where Cerbos fits when teams need fine-grained authorization.

Authentik and Keycloak solve the same identity problem

Authentik and Keycloak both belong in the identity provider category. An identity provider, or IdP, creates, manages, and verifies digital identities so downstream applications can trust a login event and receive identity claims through standards such as SAML, OAuth2, and OpenID Connect.

Both tools can centralize authentication across applications. Both can support single sign-on, multi-factor authentication, and protocol-based integrations. Both can sit at the center of a self-hosted identity stack. That is why treating Authentik as only a lightweight login helper and Keycloak as the default enterprise IdP would be misleading.

The difference is in operating style. Authentik is a Python-based IdP with proxy mode, customizable flows, an admin UI, impersonation support for debugging and user assistance, and a Remote Access Component for RDP, SSH, and VNC. Keycloak is a Java-based identity and access management system with long-standing enterprise use, federation with external identity providers, built-in clustering, and broad protocol support.

The short version is simple. Authentik is flexible and workflow-oriented. Keycloak is mature and enterprise-oriented. Both still need help when authorization becomes fine-grained, contextual, and spread across many services.

Authentik profile

Authentik is a self-hosted identity provider that handles authentication with MFA, SSO, OIDC, OAuth2, SAML, and LDAP. It can also act as a reverse proxy, which lets teams enforce authentication and MFA in front of applications that do not support those features directly.

The main appeal is flexibility. Authentik supports WebAuthn and passkeys, multiple MFA methods, custom flows and stages, GeoIP checks, impersonation for debugging, and an admin UI for managing users, flows, and policies. For teams with a mix of newer apps and older services, proxy mode can be practical because it brings a more consistent login pattern to apps that were not designed for SSO.

The trade-off is setup effort. Even simple deployments can involve multiple stages. Advanced scenarios may require custom Python code. Resource use is heavier than lighter tools, and double-login issues can appear when apps do not support SSO natively.

Authentik fits teams that want a flexible self-hosted IdP and are comfortable investing time in flow design. It is less suitable when the priority is a minimal identity layer with low ongoing configuration work.

Keycloak profile

Keycloak is a self-hosted Java-based identity and access management system. It focuses mainly on authentication and supports SSO, MFA, social logins, and federation with external identity providers. Keycloak is widely used in enterprise and legacy environments because it supports major auth protocols and integrates with existing directories.

Keycloak supports OIDC, OAuth2, and SAML. It also supports federation with LDAP, Active Directory, FreeIPA, and Kerberos. Admin and user self-service consoles, REST APIs, container-friendly deployment, and built-in clustering make Keycloak a practical option for teams that already expect enterprise IAM patterns.

The trade-off is operational weight. Keycloak can be complex to set up, tune, upgrade, and extend. Performance tuning often needs manual work. Custom extensions and upgrades can require significant effort, and documentation gaps can slow down implementation.

Keycloak fits teams that need stability, protocol coverage, federation, and enterprise familiarity. It is less suitable when the team needs a lighter IdP or wants to avoid heavier infrastructure and tuning work.

Authentik vs Keycloak feature comparison

If you are comparing Authentik vs Keycloak, start with the shared capabilities first. Both tools can support central login, SSO, MFA, and standards-based integration. The difference is how each tool packages those capabilities and what operational burden comes with them.

  • MFA and SSO: Both Authentik and Keycloak support multi-factor authentication and single sign-on, so MFA should not be treated as a differentiator by itself. The practical difference is that Authentik emphasizes proxy mode for apps without native support, while Keycloak emphasizes broad IdP and federation patterns.
  • Protocols: Authentik supports OIDC, OAuth2, SAML, and LDAP. Keycloak supports OIDC, OAuth2, and SAML, and is commonly used where directory federation and enterprise protocol coverage are key requirements.
  • Legacy access: Authentik can wrap legacy systems through proxy mode and also includes a Remote Access Component for RDP, SSH, and VNC. Keycloak is commonly used for federation with LDAP, Active Directory, FreeIPA, and Kerberos.
  • Admin experience: Authentik provides an admin UI for users, flows, and policies, plus impersonation support for debugging and assistance. Keycloak provides user self-service and admin consoles with REST APIs.
  • Operations: Authentik is flexible but can be complex, especially when custom flows need Python scripting. Keycloak is stable once configured, but it is heavier to run and often needs careful tuning.
  • Authorization: Authentik includes group- and role-based access rules and configurable policies. Keycloak includes RBAC and resource-based rules with UMA 2.0, but most teams still use Keycloak mainly as the IdP and token issuer when fine-grained authorization is required.

Where Authentik fits best

Authentik is a good fit when the team wants one self-hosted system for SSO, MFA, proxy-based protection, and custom identity flows. The product shape suits environments where not every application supports OIDC or SAML cleanly, but the team still wants a central login and MFA layer.

Proxy mode is the main practical differentiator. It lets teams put authentication in front of services that do not have native SSO or MFA. The Remote Access Component also matters if RDP, SSH, or VNC access is part of the access strategy.

Authentik also fits support-heavy environments. Impersonation can help with debugging and user assistance, while custom flows can adapt login behavior to different groups or risk signals. GeoIP checks are one example of that flexibility.

The main caution is lock-in through configuration complexity. Once Authentik sits deep in the stack, replacing it is not trivial. Teams should treat flow design as infrastructure design, not as a quick admin-panel task.

Where Keycloak fits best

Keycloak is a good fit when the team needs a mature IdP for enterprise or legacy environments. The strongest cases are federation, directory integration, protocol coverage, and deployments where Java-based enterprise infrastructure is already normal.

Keycloak is often selected when LDAP, Active Directory, FreeIPA, or Kerberos integration matters. It also makes sense when the team needs built-in clustering for availability and scaling, or when a managed enterprise option through Red Hat is part of the procurement and support strategy.

Keycloak is not the lightest choice. Setup can be complex, tuning can take time, and upgrades or custom extensions can become real projects. That does not make Keycloak weak. It makes Keycloak a better fit for teams that expect IAM to be a substantial platform, not a small service.

The practical takeaway is that Keycloak rewards teams that need its breadth. Teams that do not need federation depth or enterprise patterns may find the operating cost higher than the benefit.

Operations and maintenance

Operations are where the Authentik vs Keycloak decision often becomes clear. Both tools are self-hosted identity infrastructure. Both need monitoring, updates, backup planning, and clear ownership. The difference is the type of complexity each one introduces.

Authentik complexity tends to come from flexibility. Custom flows, stages, policies, and proxy behavior are useful, but every customization becomes something the team must understand later. Advanced scenarios can require Python scripting, so teams should account for that skill requirement before adoption.

Keycloak complexity tends to come from platform weight. Keycloak is stable once configured, but performance tuning, clustering, upgrades, custom extensions, and documentation gaps can add work. This is especially true when Keycloak becomes the central IdP for many apps and directories.

A sensible decision starts with ownership. If the team wants configurable identity workflows and accepts scripting, Authentik is easier to justify. If the team needs enterprise IAM patterns and accepts heavier operations, Keycloak is easier to justify.

Authorization is the shared gap

Authentication answers who the user is. Authorization answers what that user, service, workload, or agent can do after sign-in. Authentik and Keycloak both help with identity and access patterns, but neither can be treated as the final answer for fine-grained, contextual authorization.

Authentik has group- and role-based access rules and configurable policies. Keycloak has RBAC and resource-based rules with UMA 2.0. Those features can be useful, but they are not the same as a dedicated policy decision point for high-volume, resource-level authorization checks across applications, APIs, workloads, service accounts, MCP servers, and AI systems.

Cerbos fits beside either IdP. Authentik or Keycloak authenticates the user and issues trusted identity data. Cerbos evaluates the authorization decision using externalized policies, attributes, roles, and context. That separation keeps login and permission logic from becoming tangled in the same system.

Cerbos is designed for fine-grained authorization, RBAC, ABAC, and PBAC, centralized audit logs, OpenTelemetry integration, and low-latency policy evaluation. It also works with any IdP, which means the same authorization layer can sit behind Authentik, Keycloak, or another authentication system.

Cerbos Hub gives policy operations structure. It is the control plane for capabilities such as policy authoring UI, programmatic policy management, and interactive playgrounds.

A practical decision framework

The best choice depends on the job. Authentik and Keycloak overlap in core identity features, so teams should avoid checkbox-only decisions. MFA, SSO, and protocol support matter, but they do not tell the whole story.

  • Choose Authentik when proxy mode, custom flows, GeoIP checks, impersonation, and remote access support are important, and the team accepts the complexity that comes with flexible identity workflows.
  • Choose Keycloak when federation, legacy directory integration, enterprise familiarity, clustering, and managed enterprise support matter more than a lightweight operating model.
  • Add Cerbos when authorization needs to move beyond IdP-level roles into fine-grained, contextual decisions across services, resources, workloads, and AI use cases.

Aram, Head of Solutions at Cerbos, has put the decision clearly: "Authentication and authorization aren’t just technical decisions. They’re business decisions. You need something that’s scalable from day one, not a black box that breaks when you actually need it to work." That is the right lens for this comparison. Pick the IdP that matches the identity job, then use a dedicated authorization layer when permissions become a product and security concern.

Key takeaways

  • Authentik and Keycloak both support SSO, MFA, and standards-based identity integration.
  • Authentik is stronger when proxy mode, custom flows, impersonation, and remote access support are central requirements.
  • Keycloak is stronger when federation, enterprise IAM patterns, clustering, and legacy directory integration are central requirements.
  • Authentik often introduces complexity through flexible flows and possible Python scripting.
  • Keycloak often introduces complexity through platform weight, tuning, upgrades, and custom extensions.
  • Neither tool should be treated as a complete answer for fine-grained authorization across complex systems.
  • Cerbos can sit beside either IdP, and supports policy operations when teams need governance around policy change.

FAQ

Is Authentik better than Keycloak?

Is Keycloak better than Authentik?

Which is easier to run Authentik or Keycloak?

Do I need Cerbos with Authentik or Keycloak?

What is the best self-hosted IdP?

Tagged in

Free policy workshop

Get your first Cerbos policy written by our team.

Book a session to talk through your requirements and walk away with a working policy.

Book a session