Azure Entra ID vs. Keycloak

Identity as a Service or as Infrastructure

Azure Entra ID and Keycloak address the same core issue: managing identities, controlling access, and securing authentication. In many architectures, both appear as “Identity Providers” and are thus functionally equated. This view is too simplistic.

The difference lies not in individual features, but in control, dependency, and strategic significance. Identity is not a side function. It determines who gets access, how systems interact, and ultimately where the sovereignty over digital identities lies. Identity is power over systems.

Azure Entra ID: Identity as a Managed Service

Azure Entra ID is Microsoft’s identity platform and is deeply integrated into the entire Microsoft ecosystem. Microsoft 365, Azure, Intune, Defender, Conditional Access—all seamlessly interconnect. For organizations consistently working within the Microsoft stack, Entra ID is effectively the standard.

Operations, high availability, updates, and a large portion of the security responsibility lie with Microsoft. This significantly reduces operational effort. Identities are no longer operated but consumed. New applications can be quickly integrated, policies centrally defined, and access controlled granularly.

This convenience is real—and simultaneously a conscious shift of power.

Closedness as a Structural Limit

Technically, Entra ID is powerful but closed. Extensions follow Microsoft’s roadmap, not necessarily the organization’s requirements. While the protocols used, such as OpenID Connect, OAuth2, or SAML, are standards-compliant, the specific implementation and operational model are not always.

Identity data, policies, and audit logs reside in a Microsoft-controlled context. Operational decisions—such as retention, tenant structure, or specific security mechanisms—are only possible within what Microsoft envisions. Those who use Entra ID implicitly choose Microsoft as the central identity authority.

A later switch is fundamentally possible, but in practice expensive and organizationally complex. Identities are deeply intertwined with applications, processes, and security concepts. The longer Entra ID is used, the greater the inertia becomes.

Keycloak: Identity as Own Infrastructure

Keycloak deliberately stands on the other side. Open Source, self-hosted, fully controllable. Whether on-premises, in Kubernetes, or in a sovereign cloud—Keycloak runs where the organization permits.

All relevant protocols are openly implemented: OpenID Connect, OAuth2, SAML. Policies are fully configurable, extensions self-determined. Integrations follow standards, not vendor logic. Identity is not consumed but shaped.

This makes Keycloak an infrastructure component—not a service.

Responsibility Instead of Comfort

The price for this control is responsibility. Keycloak must be operated, secured, monitored, and updated. High availability, backup strategies, and scaling are part of one’s own architecture. There is no illusion of convenience.

In return, there is something that managed identity cannot deliver: sovereignty. Identities do not leave one’s control. Decisions about data retention, policies, and integrations are reversible. Identity is not defined by a provider but by one’s own requirements.

Especially in platform architectures, this difference is crucial.

Regulation, Compliance, and Strategic Independence

The difference between Entra ID and Keycloak becomes particularly clear when regulatory requirements come into play. NIS-2, data protection regulations, industry-specific regulations, or governmental requirements often demand clear statements about data sovereignty, access control, and operational models.

With Keycloak, such requirements can be specifically implemented. Location, tenant separation, audit trails, and integrations can be precisely tailored to regulatory frameworks. Entra ID can cover many things—as long as it fits into Microsoft’s model. Anything beyond that becomes difficult or impossible.

Identity here is not just a technical issue but part of Governance.

Condensed Comparison

When Each Approach Makes Sense

Azure Entra ID is suitable for:

• Organizations with a clear Microsoft focus
• Microsoft 365 and Azure-centric IT
• Low requirements for identity sovereignty
• Focus on quick operation without self-responsibility

Keycloak is suitable for:

• Platforms with a long-term identity strategy
• Regulatory-sensitive environments
• Multi-cloud or hybrid architectures
• Organizations that view identity as security-critical infrastructure

Conclusion

Identity determines who has access. It also determines who exercises control.

Azure Entra ID optimizes for integration and convenience. Keycloak optimizes for control and sovereignty.

The difference is not primarily technical. It is strategic—and it has long-term effects.

Those who relinquish identity give up more than authentication. And that is precisely why one should very consciously choose who determines it.