Softwr

Networking · head to head

Eclipse Mosquitto vs Skopeo

Eclipse Mosquitto logo

Eclipse Mosquitto

Networking

Small, EPL-licensed MQTT broker that runs on hardware other brokers cannot

From
Free
Rated
-
Full reviewWebsite
Skopeo logo

Skopeo

Cloud

Inspect, copy and sign container images without pulling them

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Eclipse Mosquitto there is no clustering: Mosquitto is a single process, so high availability means building your own failover and accepting session loss on switchover.; Skopeo single-purpose: it neither builds nor runs images, so it is one tool in a chain rather than a solution
  • They diverge on capability: Eclipse Mosquitto covers MQTT 5.0 support, Skopeo covers Remote inspection.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Eclipse Mosquitto and Skopeo actually diverge.

Attributes where Eclipse Mosquitto and Skopeo differ
AttributeEclipse MosquittoSkopeo
PlatformsLinux, Windows, macOS, DockerLinux, macOS
CategoryNetworkingCloud

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 Eclipse Mosquitto

  • MQTT 5.0 support
  • Very small footprint
  • Bridging
  • WebSockets listener
  • Command line clients
  • Dynamic security plugin

Only in Skopeo

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

What people use each for

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

Eclipse Mosquitto

  • A home or building automation stack where the broker must run on the same small computer as everything elsenot Skopeo
  • An industrial gateway that buffers local telemetry and bridges selected topics to a cloud brokernot Skopeo
  • Local development and testing of MQTT clients without provisioning a cloud IoT servicenot Skopeo
  • An air-gapped deployment where a broker with no licence server and no phone-home behaviour is a requirementnot Skopeo

Skopeo

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

Where each one falls short

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

Eclipse Mosquitto

  • There is no clustering: Mosquitto is a single process, so high availability means building your own failover and accepting session loss on switchover.
  • Persistence is a local file rather than a replicated store, so a disk failure or an unclean shutdown can lose retained messages and queued QoS traffic.
  • Practical capacity is a few thousand concurrent clients on typical hardware, so a growing device fleet eventually forces a migration to a clustered broker.
  • The Eclipse Public Licence is weak copyleft rather than permissive, which some legal teams treat as a blocker when embedding the broker in a shipped commercial product.
  • There is no commercial support to buy from the project, so production incidents rely on community mailing lists or on paying a third party who happens to know the codebase.

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

Pricing, plan by plan

Eclipse Mosquitto

Free
  • Eclipse MosquittoFree
    • Eclipse Public License 2.0 with Eclipse Distribution Licence
    • MQTT 5.0, 3.1.1 and 3.1
    • No client or message limits beyond your hardware

Skopeo

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

Which should you pick?

Choose Eclipse Mosquitto if

  • You need mqtt 5.0 support.
  • You want to start without paying.
  • You work on Linux, Windows, macOS, Docker.
  • You also want very small footprint.
Eclipse Mosquitto review

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

Questions people ask

Is Eclipse Mosquitto or Skopeo better?
Neither clearly leads. Eclipse Mosquitto starts at Free and Skopeo at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Eclipse Mosquitto or Skopeo?
Eclipse Mosquitto starts at Free and Skopeo at Free.
Does Eclipse Mosquitto or Skopeo run on more platforms?
Eclipse Mosquitto runs on Linux, Windows, macOS, Docker. Skopeo runs on Linux, macOS.
Can I use Eclipse Mosquitto for free?
Both have a free tier, so you can try either at no cost before committing.
What is Eclipse Mosquitto best used for?
Eclipse Mosquitto is most often used for a home or building automation stack where the broker must run on the same small computer as everything else, an industrial gateway that buffers local telemetry and bridges selected topics to a cloud broker, local development and testing of mqtt clients without provisioning a cloud iot service, an air-gapped deployment where a broker with no licence server and no phone-home behaviour is a requirement. Of those, a home or building automation stack where the broker must run on the same small computer as everything else and an industrial gateway that buffers local telemetry and bridges selected topics to a cloud broker are not what Skopeo is typically brought in for.
What can Eclipse Mosquitto do that Skopeo cannot?
Eclipse Mosquitto covers MQTT 5.0 support, Very small footprint, Bridging, WebSockets listener. Skopeo covers Remote inspection, Registry-to-registry copy, Format conversion, Image signing.

Answered from the vendors’ own pages

Eclipse Mosquitto: Can Mosquitto be clustered?

No. It is a single process. High availability requires an external failover arrangement you build yourself.

Skopeo: Is Skopeo free?

Yes, open source with no licence fee.

Eclipse Mosquitto: What licence is it?

Eclipse Public License 2.0 alongside the Eclipse Distribution License, a weak copyleft rather than a permissive licence.

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.

Eclipse Mosquitto: How many clients can it handle?

A few thousand concurrent connections on ordinary hardware; beyond that, use a clustered broker.

Skopeo: Can Skopeo run containers?

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

Eclipse Mosquitto: Does it support MQTT 5?

Yes, along with 3.1.1 and 3.1.

Share

Related pages

More on Eclipse Mosquitto

More on Skopeo

Keep looking

Other head to heads