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Developer Tools · head to head

Atlantis vs Longhorn

Atlantis logo

Atlantis

Developer Tools

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

From
Free
Rated
-
Full reviewWebsite
Longhorn logo

Longhorn

Cloud

Open source distributed block storage for Kubernetes, incubating at the CNCF

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.; Longhorn there is no vendor and no SLA, so a production incident at three in the morning is your own problem unless you buy SUSE Rancher Prime support separately.
  • They diverge on capability: Atlantis covers Pull request plans, Longhorn covers Per-volume controllers.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Atlantis and Longhorn actually diverge.

Attributes where Atlantis and Longhorn differ
AttributeAtlantisLonghorn
PlatformsLinux, Docker, Kubernetes, Self-hostedLinux, Kubernetes
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 Longhorn

  • Per-volume controllers
  • Synchronous replication
  • Snapshots and backups
  • Volume expansion
  • Disaster recovery volumes
  • Web interface

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 Longhorn
  • Removing local applies and the credential sprawl that comes with every engineer holding production keysnot Longhorn
  • Getting pull request driven infrastructure without paying a per-user subscription for a hosted platformnot Longhorn
  • Enforcing Conftest policies as a blocking check before an apply can runnot Longhorn

Longhorn

  • An on-premises Kubernetes cluster with local disks and no SAN that needs replicated persistent volumesnot Atlantis
  • Edge sites where shipping a storage array is impractical and three nodes is the whole clusternot Atlantis
  • A K3s deployment where the storage layer must be light enough to run alongside the workloadsnot Atlantis
  • A team that wants snapshots and S3 backups of persistent volumes without paying per-node storage licencesnot 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.

Longhorn

  • There is no vendor and no SLA, so a production incident at three in the morning is your own problem unless you buy SUSE Rancher Prime support separately.
  • Synchronous replication across nodes means write latency depends on the slowest replica and the network between nodes, which makes it a poor fit for latency-sensitive databases.
  • Every replica is a full copy, so three-way replication consumes three times the raw capacity, unlike erasure-coded systems that are far more space efficient.
  • It is designed for block storage on modest clusters and does not scale to the node counts or throughput that Ceph or a commercial array handles, so growth eventually forces a migration.
  • Recovery from certain degraded states, such as a volume stuck detaching or replicas failing to rebuild, requires manual intervention and knowledge of Longhorn internals that is not widely held.

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

Longhorn

Free
  • LonghornFree
    • Apache 2.0 licensed, no licence fee
    • Community support via GitHub and Slack only
    • No vendor SLA or escalation path

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 Longhorn if

  • You need per-volume controllers.
  • You want to start without paying.
  • You work on Linux, Kubernetes.
  • You also want synchronous replication.
Longhorn review

Questions people ask

Is Atlantis or Longhorn better?
Neither clearly leads. Atlantis starts at Free and Longhorn at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Atlantis or Longhorn?
Atlantis starts at Free and Longhorn at Free.
Does Atlantis or Longhorn run on more platforms?
Atlantis runs on Linux, Docker, Kubernetes, Self-hosted. Longhorn runs on Linux, Kubernetes.
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 Longhorn is typically brought in for.
What can Atlantis do that Longhorn cannot?
Atlantis covers Pull request plans, Comment driven apply, Workspace locking, Policy checking. Longhorn covers Per-volume controllers, Synchronous replication, Snapshots and backups, Volume expansion.

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.

Longhorn: Who do we call when it breaks?

Nobody, unless you buy SUSE Rancher Prime, which includes commercial support for Longhorn. This is the decisive question for production use.

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.

Longhorn: How much capacity does replication cost?

Full copies, so three replicas means three times the raw capacity. Budget accordingly rather than assuming erasure coding efficiency.

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.

Longhorn: Is it suitable for production databases?

For modest workloads yes, but synchronous replication adds write latency and high-transaction databases usually want something faster.

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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