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Developer Tools · head to head

Atlantis vs Cilium

Atlantis logo

Atlantis

Developer Tools

Runs Terraform plan and apply from pull request comments, self-hosted and free

From
Free
Rated
-
Full reviewWebsite
Cilium logo

Cilium

Cloud

eBPF-based networking, observability and security for Kubernetes

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Atlantis there is no company, no service level agreement and no paid support at any price, and the six maintainers are volunteers with day jobs, which some risk committees will not accept for a component holding production cloud credentials.; Cilium requires a recent Linux kernel, which rules out older distributions and some managed environments
  • They diverge on capability: Atlantis covers Pull request plans, Cilium covers eBPF datapath.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Atlantis and Cilium actually diverge.

Attributes where Atlantis and Cilium differ
AttributeAtlantisCilium
PlatformsLinux, Docker, Kubernetes, Self-hostedKubernetes, Linux
CategoryDeveloper ToolsCloud

Identical on both: starting price (Free), pricing model (Open source, no licence fee), 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 Atlantis

  • Pull request plans
  • Comment driven apply
  • Workspace locking
  • Policy checking
  • Multi-platform webhooks
  • Custom workflows

Only in Cilium

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

What people use each for

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

Atlantis

  • Making Terraform review meaningful by putting the actual plan output in front of the approvernot Cilium
  • Removing local applies and the credential sprawl that comes with every engineer holding production keysnot Cilium
  • Getting pull request driven infrastructure without paying a per-user subscription for a hosted platformnot Cilium
  • Enforcing Conftest policies as a blocking check before an apply can runnot Cilium

Cilium

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

Where each one falls short

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

Atlantis

  • There is no company, no service level agreement and no paid support at any price, and the six maintainers are volunteers with day jobs, which some risk committees will not accept for a component holding production cloud credentials.
  • The security surface is inherently sharp, because it is an internet-reachable webhook endpoint that executes applies with privileged credentials, gated by pull request comment authorisation that is coarse next to a real policy engine.
  • It is stateful, holding a working directory and lock database on local disk, so high availability and horizontal scaling are awkward and you own upgrades, webhook plumbing, secret rotation and the host itself.
  • It lacks the features that distinguish the commercial alternatives, with no native drift detection, no cost estimation, no managed state interface and no policy engine beyond the Conftest integration.
  • Terragrunt and monorepo layouts are not first-class, requiring hand-written custom workflows and repository configuration that becomes a growing maintenance burden as the number of repositories increases.

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

Pricing, plan by plan

Atlantis

Free
  • AtlantisFree
    • Apache-2.0, no usage limits and no seat count
    • No commercial edition and no paid support tier
    • Community support through GitHub and the CNCF Slack channel

Cilium

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

Which should you pick?

Choose Atlantis if

  • You need pull request plans.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want comment driven apply.
Atlantis review

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

Questions people ask

Is Atlantis or Cilium better?
Neither clearly leads. Atlantis starts at Free and Cilium at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Atlantis or Cilium?
Atlantis starts at Free and Cilium at Free.
Does Atlantis or Cilium run on more platforms?
Atlantis runs on Linux, Docker, Kubernetes, Self-hosted. Cilium runs on Kubernetes, Linux.
Can I use Atlantis for free?
Both have a free tier, so you can try either at no cost before committing.
What is Atlantis best used for?
Atlantis is most often used for making terraform review meaningful by putting the actual plan output in front of the approver, removing local applies and the credential sprawl that comes with every engineer holding production keys, getting pull request driven infrastructure without paying a per-user subscription for a hosted platform, enforcing conftest policies as a blocking check before an apply can run. Of those, making terraform review meaningful by putting the actual plan output in front of the approver and removing local applies and the credential sprawl that comes with every engineer holding production keys are not what Cilium is typically brought in for.
What can Atlantis do that Cilium cannot?
Atlantis covers Pull request plans, Comment driven apply, Workspace locking, Policy checking. Cilium covers eBPF datapath, Identity-based policy, Hubble observability, Sidecar-free mesh.

Answered from the vendors’ own pages

Atlantis: Is there a company behind Atlantis?

No. It runs as a series of LF Projects under the Linux Foundation and is maintained by volunteers. There is no vendor to buy support from and no service level agreement.

Cilium: Is Cilium free?

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

Atlantis: Is it a CNCF project?

No. It uses a channel in the CNCF Slack, which is often misread as membership, but the project sits under LF Projects rather than the CNCF.

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.

Atlantis: Does it work with OpenTofu?

Yes, there is a dedicated integration guide alongside Terraform, and it also has configuration for working with hosted Terraform backends.

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.

Atlantis: What does it not do that a paid platform does?

Drift detection, cost estimation, a managed state and run interface, and a real policy engine. Atlantis does pull request plan and apply well and stops there.

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