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Cloud · head to head

Cilium vs Keycloak

Cilium logo

Cilium

Cloud

eBPF-based networking, observability and security for Kubernetes

From
Free
Free plan
Yes
Full reviewWebsite
Keycloak logo

Keycloak

Developer Tools

Open-source identity and access management server.

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Cilium requires a recent Linux kernel, which rules out older distributions and some managed environments; Keycloak requires self-hosted deployment and operational expertise to install, configure and maintain
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Cilium and Keycloak actually diverge.

Attributes where Cilium and Keycloak differ
AttributeCiliumKeycloak
Pricing modelOpen source, no licence feeopen-source
PlatformsKubernetes, LinuxSelf-hosted, Docker, Kubernetes, Linux, Windows, API
CategoryCloudDeveloper Tools

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Cilium

  • eBPF datapath
  • Identity-based policy
  • Hubble observability
  • Sidecar-free mesh

Only in Keycloak

Nothing recorded that Cilium does not also cover.

What people use each for

The jobs each tool is most often brought in to do.

Cilium

  • Kubernetes networking at a scale where iptables-based CNI performance degradesnot Keycloak
  • Network policy expressed on workload identity rather than fragile IP rulesnot Keycloak
  • Seeing which services actually talk to each other, and what policy is droppingnot Keycloak

Keycloak

  • Organisations requiring self-hosted identity infrastructure for compliance or data residencynot Cilium
  • Companies with existing LDAP/Active Directory systems needing federated authenticationnot Cilium
  • Open-source projects and communities requiring free IAM without licensing costsnot Cilium
  • Enterprises building custom identity workflows requiring fine-grained authorisationnot Cilium
  • Teams with sufficient operational expertise to manage infrastructurenot Cilium

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Cilium

  • Requires a recent Linux kernel, which rules out older distributions and some managed environments
  • eBPF is genuinely hard to debug when it misbehaves, and the skill is rare on most teams
  • Broad scope — CNI, policy, mesh, observability — means the learning curve covers several domains at once

Keycloak

  • Requires self-hosted deployment and operational expertise to install, configure and maintain
  • No managed cloud option provided by Red Hat; organisations must operate infrastructure themselves or use third-party distributions
  • Clustering and high-availability configurations require additional operational knowledge
  • Community support only; commercial support requires third-party vendors or distributions

Pricing, plan by plan

Cilium

Free
  • CiliumFree
    • Full functionality
    • No usage limits
    • Community support

Keycloak

Free
  • Open-sourceFree
    • Full platform functionality
    • Self-hosted deployment
    • Community support

Which should you pick?

Choose Cilium if

  • You need ebpf datapath.
  • You want to start without paying.
  • You work on Kubernetes, Linux.
  • You also want identity-based policy.
Cilium review

Choose Keycloak if

  • You want to start without paying.
  • You work on Self-hosted, Docker, Kubernetes, Linux, Windows, API.
Keycloak review

Questions people ask

Is Cilium or Keycloak better?
Neither clearly leads. Cilium starts at Free and Keycloak at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cilium or Keycloak?
Cilium starts at Free and Keycloak at Free.
Does Cilium or Keycloak run on more platforms?
Cilium runs on Kubernetes, Linux. Keycloak runs on Self-hosted, Docker, Kubernetes, Linux, Windows, API.
Can I use Cilium for free?
Both have a free tier, so you can try either at no cost before committing.
What is Cilium best used for?
Cilium is most often used for kubernetes networking at a scale where iptables-based cni performance degrades, network policy expressed on workload identity rather than fragile ip rules, seeing which services actually talk to each other, and what policy is dropping. Of those, kubernetes networking at a scale where iptables-based cni performance degrades and network policy expressed on workload identity rather than fragile ip rules are not what Keycloak is typically brought in for.
What can Cilium do that Keycloak cannot?
Cilium covers eBPF datapath, Identity-based policy, Hubble observability, Sidecar-free mesh.

Answered from the vendors’ own pages

Cilium: Is Cilium free?

Yes, open source and CNCF-graduated. Isovalent sells an enterprise distribution and support.

Keycloak: What protocols does Keycloak support?

Keycloak supports OpenID Connect, OAuth 2.0 and SAML 2.0 protocols for authentication and authorisation.

Source
Cilium: What does eBPF change?

It lets Cilium run packet-processing programs inside the kernel instead of relying on iptables rule chains, which behave poorly as the number of services grows.

Keycloak: Can Keycloak integrate with existing user directories?

Yes. Keycloak supports user federation with LDAP and Active Directory systems, allowing organisations to leverage existing user directories.

Source
Cilium: Does Cilium replace a service mesh?

It can cover much of what a mesh does without sidecars, though full mesh feature sets still favour Istio or Linkerd.

Keycloak: Is Keycloak free?

Yes. Keycloak is fully open-source and free to deploy and use. No licensing fees are required.

Source
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