Softwr

Cloud · head to head

Skopeo vs containerd

Skopeo logo

Skopeo

Cloud

Inspect, copy and sign container images without pulling them

From
Free
Rated
-
Full reviewWebsite
containerd logo

containerd

Cloud

Industry-standard container runtime, and the engine inside Docker

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Skopeo single-purpose: it neither builds nor runs images, so it is one tool in a chain rather than a solution; containerd not a developer-facing tool: there is no build command and the CLI is deliberately minimal, so it needs companions like nerdctl or Buildah
  • They diverge on capability: Skopeo covers Remote inspection, containerd covers Full container lifecycle.

Where they differ

Only the attributes on which Skopeo and containerd actually diverge.

Attributes where Skopeo and containerd differ
AttributeSkopeocontainerd
PlatformsLinux, macOSLinux, Windows

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 Skopeo

  • Remote inspection
  • Registry-to-registry copy
  • Format conversion
  • Image signing

Only in containerd

  • Full container lifecycle
  • CRI support
  • OCI compliant
  • Snapshotter plugins
  • Namespaces
  • Stable API

What people use each for

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

Skopeo

  • Promoting images between staging and production registries without a round tripnot containerd
  • Inspecting an image’s contents before deciding to deploy itnot containerd
  • Mirroring images into an air-gapped or internal registrynot containerd

containerd

  • Running the container runtime under a Kubernetes cluster after the Docker shim removalnot Skopeo
  • Building a platform or PaaS that needs to execute containersnot Skopeo
  • Reducing the moving parts on nodes that only ever run Kubernetes workloadsnot Skopeo
  • Embedding container execution inside another productnot Skopeo

Where each one falls short

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

Skopeo

  • Single-purpose: it neither builds nor runs images, so it is one tool in a chain rather than a solution
  • Command syntax with transport prefixes such as docker:// is unusual and trips people up initially
  • Documentation is sparse compared with the rest of the container ecosystem

containerd

  • Not a developer-facing tool: there is no build command and the CLI is deliberately minimal, so it needs companions like nerdctl or Buildah
  • Debugging is lower-level than Docker, and error messages assume knowledge of the runtime internals
  • Documentation is aimed at platform engineers, so newcomers usually find Docker or Podman material more useful
  • No image building at all — that is out of scope by design

Pricing, plan by plan

Skopeo

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

containerd

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

Which should you pick?

Choose Skopeo if

  • You need remote inspection.
  • You want to start without paying.
  • You work on Linux, macOS.
  • You also want registry-to-registry copy.
Skopeo review

Choose containerd if

  • You need full container lifecycle.
  • You want to start without paying.
  • You work on Linux, Windows.
  • You also want cri support.
containerd review

Questions people ask

Is Skopeo or containerd better?
Neither clearly leads. Skopeo starts at Free and containerd at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Skopeo or containerd?
Skopeo starts at Free and containerd at Free.
Does Skopeo or containerd run on more platforms?
Skopeo runs on Linux, macOS. containerd runs on Linux, Windows.
Can I use Skopeo for free?
Both have a free tier, so you can try either at no cost before committing.
What is Skopeo best used for?
Skopeo is most often used for promoting images between staging and production registries without a round trip, inspecting an image’s contents before deciding to deploy it, mirroring images into an air-gapped or internal registry. Of those, promoting images between staging and production registries without a round trip and inspecting an image’s contents before deciding to deploy it are not what containerd is typically brought in for.
What can Skopeo do that containerd cannot?
Skopeo covers Remote inspection, Registry-to-registry copy, Format conversion, Image signing. containerd covers Full container lifecycle, CRI support, OCI compliant, Snapshotter plugins.

Answered from the vendors’ own pages

Skopeo: Is Skopeo free?

Yes, open source with no licence fee.

containerd: Is containerd free?

Yes. It is an open-source CNCF graduated project with no licence fee.

Skopeo: Why copy images without pulling them?

A registry-to-registry copy avoids downloading and re-uploading gigabytes, which is faster and much cheaper on bandwidth in CI.

containerd: Do I need containerd if I use Docker?

You already have it. Docker uses containerd underneath to run containers; it is not an alternative you install separately.

Skopeo: Can Skopeo run containers?

No. It only inspects, copies, signs and deletes images. Running them is Podman’s or Docker’s job.

containerd: Why did Kubernetes drop Docker for containerd?

Kubernetes talks to runtimes through the Container Runtime Interface. Docker did not speak CRI natively and needed a shim, so Kubernetes removed the shim and talks to containerd directly, which Docker was already using anyway.

containerd: Can containerd build images?

No. Image building is deliberately out of scope. Tools such as Buildah, BuildKit or Docker handle that.

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