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Networking · head to head

Eclipse Mosquitto vs Packer

Eclipse Mosquitto logo

Eclipse Mosquitto

Networking

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

From
Free
Rated
-
Full reviewWebsite
Packer logo

Packer

Cloud

Build automated machine images

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.; Packer packer 1.10.0 and later is licensed under the Business Source License 1.1 with IBM Corporation as licensor, not an OSI open source licence
  • They diverge on capability: Eclipse Mosquitto covers MQTT 5.0 support, Packer covers Image building.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

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

Attributes where Eclipse Mosquitto and Packer differ
AttributeEclipse MosquittoPacker
Pricing modelOpen source, no licence feeopen-source
PlatformsLinux, Windows, macOS, DockerLinux, Windows, Mac
CategoryNetworkingCloud
FoundedUnknown2013

Identical on both: starting price (Free), 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 Packer

  • Image building
  • Multi-platform support
  • Provisioners
  • Builders
  • Post-processors
  • Variables
  • Data sources
  • Validation

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 Packer
  • An industrial gateway that buffers local telemetry and bridges selected topics to a cloud brokernot Packer
  • Local development and testing of MQTT clients without provisioning a cloud IoT servicenot Packer
  • An air-gapped deployment where a broker with no licence server and no phone-home behaviour is a requirementnot Packer

Packer

  • Building identical machine images for multiple clouds from one templatenot Eclipse Mosquitto
  • Baking golden AMIs and VM images into a CI pipelinenot Eclipse Mosquitto
  • Creating immutable infrastructure artifacts consumed by Terraformnot 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.

Packer

  • Packer 1.10.0 and later is licensed under the Business Source License 1.1 with IBM Corporation as licensor, not an OSI open source licence
  • The Additional Use Grant forbids offering Packer to third parties on a hosted or embedded basis in a paid product that competes with IBM's paid versions of Packer
  • Each version converts to the MPL 2.0 Change License only four years after that version is first published, and the Change Date is set separately per version
  • Alternative licensing for uses outside the grant must be arranged with the licensor rather than taken under the public licence

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

Packer

Free
  • Open SourceFree
    • Multi-platform image building
    • Template-driven
    • Provisioner 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 Packer if

  • You need image building.
  • You want to start without paying.
  • You work on Linux, Windows, Mac.
  • You also want multi-platform support.
Packer review

Questions people ask

Is Eclipse Mosquitto or Packer better?
Neither clearly leads. Eclipse Mosquitto starts at Free and Packer at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Eclipse Mosquitto or Packer?
Eclipse Mosquitto starts at Free and Packer at Free.
Does Eclipse Mosquitto or Packer run on more platforms?
Eclipse Mosquitto runs on Linux, Windows, macOS, Docker. Packer runs on Linux, Windows, Mac.
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 Packer is typically brought in for.
What can Eclipse Mosquitto do that Packer cannot?
Eclipse Mosquitto covers MQTT 5.0 support, Very small footprint, Bridging, WebSockets listener. Packer covers Image building, Multi-platform support, Provisioners, Builders.

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.

Packer: How much does HashiCorp Packer cost?

Packer does not publish specific pricing on its website. The open-source Packer tool is free, while HCP Packer (HashiCorp's cloud-hosted version) offers a free trial, but detailed pricing requires contacting HashiCorp.

Source
Eclipse Mosquitto: What licence is it?

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

Eclipse Mosquitto: How many clients can it handle?

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

Eclipse Mosquitto: Does it support MQTT 5?

Yes, along with 3.1.1 and 3.1.

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