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Cloud · head to head

K3s vs Longhorn

K3s logo

K3s

Cloud

Lightweight certified Kubernetes distribution in a single binary

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: K3s the SQLite default is single-server only; highly available control planes need etcd or an external datastore, which removes much of the simplicity; 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: K3s covers Single binary, Longhorn covers Per-volume controllers.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which K3s and Longhorn actually diverge.

Attributes where K3s and Longhorn differ
AttributeK3sLonghorn
PlatformsLinux, ARM, Self-hostedLinux, Kubernetes

Identical on both: starting price (Free), pricing model (Open source, no licence fee), free tier (Yes), user rating (Not yet rated), category (Cloud).

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 K3s

  • Single binary
  • SQLite by default
  • Certified conformant
  • Batteries included
  • Low resource footprint
  • Simple install

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.

K3s

  • Kubernetes on edge sites and IoT hardware where full clusters will not fitnot Longhorn
  • Development and CI clusters that must start fast and cost nothingnot Longhorn
  • Small production clusters where full Kubernetes is more operations than the workload justifiesnot Longhorn
  • Teaching and learning Kubernetes without cloud spendnot Longhorn

Longhorn

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

Where each one falls short

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

K3s

  • The SQLite default is single-server only; highly available control planes need etcd or an external datastore, which removes much of the simplicity
  • Bundled components such as Traefik are opinionated defaults that larger teams often strip out and replace
  • Removed in-tree cloud provider integrations mean cloud-specific features need external controllers
  • Aimed at small and edge clusters, so very large deployments are better served by a standard distribution

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

K3s

Free
  • K3sFree
    • Full functionality
    • No usage limits
    • Community support

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 K3s if

  • You need single binary.
  • You want to start without paying.
  • You work on Linux, ARM, Self-hosted.
  • You also want sqlite by default.
K3s 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 K3s or Longhorn better?
Neither clearly leads. K3s 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, K3s or Longhorn?
K3s starts at Free and Longhorn at Free.
Does K3s or Longhorn run on more platforms?
K3s runs on Linux, ARM, Self-hosted. Longhorn runs on Linux, Kubernetes.
Can I use K3s for free?
Both have a free tier, so you can try either at no cost before committing.
What is K3s best used for?
K3s is most often used for kubernetes on edge sites and iot hardware where full clusters will not fit, development and ci clusters that must start fast and cost nothing, small production clusters where full kubernetes is more operations than the workload justifies, teaching and learning kubernetes without cloud spend. Of those, kubernetes on edge sites and iot hardware where full clusters will not fit and development and ci clusters that must start fast and cost nothing are not what Longhorn is typically brought in for.
What can K3s do that Longhorn cannot?
K3s covers Single binary, SQLite by default, Certified conformant, Batteries included. Longhorn covers Per-volume controllers, Synchronous replication, Snapshots and backups, Volume expansion.

Answered from the vendors’ own pages

K3s: Is K3s free?

Yes. K3s is open source with no licence fee. SUSE sells commercial support around Rancher separately.

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.

K3s: Is K3s real Kubernetes?

Yes. It is CNCF-certified conformant, so standard manifests, kubectl and Helm charts work without modification.

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.

K3s: Why is K3s smaller than Kubernetes?

It strips legacy, alpha and in-tree cloud provider code, packages everything as one binary, and defaults to SQLite instead of etcd.

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.

K3s: Can K3s run in production?

Yes, and it does, particularly at the edge and for small clusters. For a highly available control plane you need to move off the SQLite default to etcd or an external datastore.

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