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Networking · head to head

Eclipse Mosquitto vs MQTT

Eclipse Mosquitto logo

Eclipse Mosquitto

Networking

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

From
Free
Rated
-
Full reviewWebsite
MQTT logo

MQTT

Smart Home

Lightweight messaging protocol for IoT devices

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.; MQTT mQTT is an open-source protocol standard with no commercial pricing; not a commercial product
  • They diverge on capability: Eclipse Mosquitto covers MQTT 5.0 support, MQTT covers Publish-Subscribe.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

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

Attributes where Eclipse Mosquitto and MQTT differ
AttributeEclipse MosquittoMQTT
Pricing modelOpen source, no licence feeopen-source
PlatformsLinux, Windows, macOS, DockerAny platform, Embedded devices, Cloud, Edge computing
CategoryNetworkingSmart Home
FoundedUnknown1999

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 MQTT

  • Publish-Subscribe
  • Lightweight
  • QoS Levels
  • Retained Messages
  • IoT platforms
  • Home automation
  • Cloud services
  • Edge devices

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

MQTT

  • IoT messagingnot Eclipse Mosquitto
  • Sensor datanot Eclipse Mosquitto
  • Real-time updatesnot Eclipse Mosquitto
  • Device telemetrynot 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.

MQTT

  • MQTT is an open-source protocol standard with no commercial pricing; not a commercial product

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

MQTT

Free
  • Open ProtocolFree
    • Publish-subscribe
    • Lightweight
    • QoS levels

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 MQTT if

  • You need publish-subscribe.
  • You want to start without paying.
  • You work on Any platform, Embedded devices, Cloud, Edge computing.
  • You also want lightweight.
MQTT review

Questions people ask

Is Eclipse Mosquitto or MQTT better?
Neither clearly leads. Eclipse Mosquitto starts at Free and MQTT at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Eclipse Mosquitto or MQTT?
Eclipse Mosquitto starts at Free and MQTT at Free.
Does Eclipse Mosquitto or MQTT run on more platforms?
Eclipse Mosquitto runs on Linux, Windows, macOS, Docker. MQTT runs on Any platform, Embedded devices, Cloud, Edge computing.
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 MQTT is typically brought in for.
What can Eclipse Mosquitto do that MQTT cannot?
Eclipse Mosquitto covers MQTT 5.0 support, Very small footprint, Bridging, WebSockets listener. MQTT covers Publish-Subscribe, Lightweight, QoS Levels, Retained Messages.

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.

MQTT: Does MQTT have a commercial license cost?

MQTT is an open-source communication protocol and standard. No pricing is published because MQTT itself is not a commercial product for sale.

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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