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Cloud · head to head

Cilium vs Datadog

Cilium logo

Cilium

Cloud

eBPF-based networking, observability and security for Kubernetes

From
Free
Rated
-
Full reviewWebsite
Datadog logo

Datadog

Technology

Modern monitoring & security

From
$15/month
Rated
-
Full reviewWebsite

The short version

  • Only Cilium has a free tier, so it costs nothing to try first.
  • Each has a real cost: Cilium requires a recent Linux kernel, which rules out older distributions and some managed environments; Datadog consumption-based pricing model makes costs hard to predict and can scale quickly
  • They diverge on capability: Cilium covers eBPF datapath, Datadog covers Infrastructure monitoring.

Where they differ

Only the attributes on which Cilium and Datadog actually diverge.

Attributes where Cilium and Datadog differ
AttributeCiliumDatadog
Starting priceFree$15/month
Pricing modelOpen source, no licence feeUnknown
Free tierYesNo
PlatformsKubernetes, LinuxWeb, Linux, Windows, macOS
CategoryCloudTechnology
FoundedUnknown2010

Identical on both: 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 Datadog

  • Infrastructure monitoring
  • Application performance monitoring
  • Log management
  • Real user monitoring
  • Synthetic monitoring
  • Security monitoring
  • Network monitoring
  • Serverless monitoring

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 Datadog
  • Network policy expressed on workload identity rather than fragile IP rulesnot Datadog
  • Seeing which services actually talk to each other, and what policy is droppingnot Datadog

Datadog

  • Infrastructure monitoringnot Cilium
  • Application performancenot Cilium
  • Security monitoringnot Cilium
  • Log analysisnot Cilium
  • Cloud monitoringnot 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

Datadog

  • Consumption-based pricing model makes costs hard to predict and can scale quickly
  • Add-on modules significantly increase costs: custom metrics, indexed spans, extended retention
  • No free tier for production monitoring
  • High costs for organizations with large amounts of log data or high-cardinality metrics

Pricing, plan by plan

Cilium

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

Datadog

$15/month
  • Infrastructure Monitoring$15/month
    • Host monitoring
    • Basic dashboards
  • APM$31/month
    • Application performance monitoring
    • Trace collection
  • Log Management$0.1/gb
    • Log indexing
    • Search and filter

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 Datadog if

  • You need infrastructure monitoring.
  • You work on Web, Linux, Windows, macOS.
  • You also want application performance monitoring.
Datadog review

Questions people ask

Is Cilium or Datadog better?
Neither clearly leads. Cilium starts at Free and Datadog at $15/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cilium or Datadog?
Cilium has a free tier; the other does not. Paid plans start at Free for Cilium and $15/month for Datadog.
Does Cilium or Datadog run on more platforms?
Cilium runs on Kubernetes, Linux. Datadog runs on Web, Linux, Windows, macOS.
Can I use Cilium for free?
Yes. Cilium has a free tier, so you can try it without paying. Datadog starts at $15/month.
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 Datadog is typically brought in for.
What can Cilium do that Datadog cannot?
Cilium covers eBPF datapath, Identity-based policy, Hubble observability, Sidecar-free mesh. Datadog covers Infrastructure monitoring, Application performance monitoring, Log management, Real user monitoring.

Answered from the vendors’ own pages

Cilium: Is Cilium free?

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

Datadog: How is Datadog pricing structured?

Datadog uses consumption-based pricing tied to data volume ingested, hosts monitored, and products enabled. Infrastructure Monitoring starts at $15/host/month, APM at $31/host/month, and Log Management at $0.10/GB for indexed logs.

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.

Datadog: Does Datadog offer a free tier?

Datadog offers a free trial but not a permanent free tier for production monitoring. Pricing begins with paid plans only.

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.

Datadog: What integrations does Datadog support?

Datadog offers 1000+ built-in integrations including AWS, Kubernetes, Docker, Azure, GCP, and most major cloud platforms and services.

Source
Datadog: Can Datadog monitor Kubernetes clusters?

Yes. The Datadog Agent runs as a DaemonSet to provide real-time visibility into pods, nodes, deployments, and control-plane health across major Kubernetes distributions including EKS, AKS, GKE, OpenShift, and others.

Source
Datadog: How can I reduce Datadog costs?

Datadog bills based on indexed logs, custom metrics, and high-cardinality tags. Costs can be unpredictable and may run 2-3x estimates. Prepaying annually can secure 5-15% discounts.

Source
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