EKS vs AKS: how to choose
EKS and AKS both run managed Kubernetes, and the choice is nearly always decided by which cloud the organisation is already committed to rather than by the clusters themselves. If your identity lives in Entra ID and your commercial relationship is with Microsoft, AKS is the answer. If your infrastructure is in AWS, EKS is.
Where they genuinely differ is identity and integration ergonomics. AKS's tight coupling to Entra ID means Kubernetes RBAC can be driven by the same groups that govern everything else in the organisation, which is a real advantage in a company that already runs on Microsoft identity. EKS's advantage is the surrounding ecosystem: more third-party tooling assumes AWS first, and more operational knowledge is written down for it.
Neither is meaningfully behind the other on Kubernetes itself. Both track upstream at a reasonable pace, both offer managed node pools, cluster autoscaling and workload identity.
Decision matrix: which one fits your situation
| Your situation | Use | Why |
|---|---|---|
| Organisation runs on Entra ID and Microsoft licensing | AKS | Cluster RBAC driven by existing groups, one commercial relationship, one support path. |
| Infrastructure and data already in AWS | EKS | Avoids cross-cloud egress, a second identity model, and a second set of runbooks. |
| Windows containers in the mix | AKS | Windows node pools are better supported and better documented on Azure. |
| Team wants the largest ecosystem and hiring pool | EKS | More tooling, more written operational knowledge, more engineers who have run it. |
| Cost-sensitive small cluster | AKS | The free control plane tier removes the per-cluster charge, at the cost of an uptime SLA. |
Identity is the part that actually differs
On AKS, Entra ID integration means a user's group membership can map directly to Kubernetes RBAC, and workload identity federates a Kubernetes service account to an Entra application. For an organisation where joiners and leavers are already handled centrally, this removes a whole class of access drift — revoking someone in the directory revokes their cluster access.
On EKS the equivalent runs through IAM: users and roles are mapped to Kubernetes groups, and workloads assume roles via IRSA or Pod Identity. It is equally capable and generally better documented, but if your organisation's source of truth for people is Entra ID, you are bridging two directories rather than using one.
Frequently asked questions
Is the AKS free tier suitable for production?
For non-critical workloads, yes. The distinction is the control plane SLA, not the control plane's behaviour — the free tier has no financially backed uptime guarantee. Your workloads keep running if the API server is briefly unavailable, but you cannot deploy, scale or self-heal during that window. Pay for the tier with an SLA for anything where that matters.
Which has better Windows container support?
AKS, clearly. Both support Windows node pools, but Azure's documentation, defaults and support experience assume Windows is a first-class case. If Windows containers are a meaningful part of the estate, that alone is enough to decide it.
How hard is it to migrate between them?
The Kubernetes objects port with little change. The work is everywhere else: identity mappings, storage classes and persistent volume data, ingress and load balancer annotations, image registry, secrets backend, and every piece of infrastructure-as-code that references cloud-specific resources. Plan the data migration first — it is almost always the critical path, not the manifests.
Do either lock me in?
Not at the Kubernetes layer, which is the same everywhere. Lock-in accumulates in what the cluster talks to — the managed database, the message queue, the object store and the identity provider. If portability genuinely matters, spend the effort keeping those dependencies behind interfaces rather than choosing a cluster on that basis.
