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Networking · head to head

Eclipse Mosquitto vs Zabbix

Eclipse Mosquitto logo

Eclipse Mosquitto

Networking

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

From
Free
Rated
-
Full reviewWebsite
Zabbix logo

Zabbix

Networking

Open source infrastructure and network monitoring with distributed proxies and templating

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.; Zabbix the database is the scaling limit, and high frequency polling grows history tables fast enough that untuned installations hit housekeeping stalls and query timeouts within months.
  • They diverge on capability: Eclipse Mosquitto covers MQTT 5.0 support, Zabbix covers Agent and agentless collection.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

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

Attributes where Eclipse Mosquitto and Zabbix differ
AttributeEclipse MosquittoZabbix
PlatformsLinux, Windows, macOS, DockerLinux, Docker, Kubernetes, Web

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

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 Zabbix

  • Agent and agentless collection
  • Templates
  • Low-level discovery
  • Distributed proxies
  • Trigger expressions
  • Escalation actions

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

Zabbix

  • A service provider monitoring thousands of customer devices where per-device commercial licensing is the largest line itemnot Eclipse Mosquitto
  • Branch or industrial sites with unreliable links that need local collection and bufferingnot Eclipse Mosquitto
  • Mixed estates where the same tool must poll SNMP switches, Linux hosts, Windows servers and Java applicationsnot Eclipse Mosquitto
  • Replacing an aging Nagios installation while keeping script-based checks that already existnot 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.

Zabbix

  • The database is the scaling limit, and high frequency polling grows history tables fast enough that untuned installations hit housekeeping stalls and query timeouts within months.
  • Initial configuration is heavy; getting useful alerting rather than noise requires understanding trigger expressions, macros and template inheritance, which is a multi-week learning curve for a team new to it.
  • The AGPLv3 change at version 7.0 affects anyone offering Zabbix over a network as part of a commercial service, and that obligation is easy to inherit accidentally during an upgrade.
  • The web interface is functional rather than pleasant, and many sites end up running Grafana alongside it purely for presentation, which is a second system to maintain.
  • Upgrades between major versions touch the database schema and can take hours on large history tables, so the maintenance window is proportional to how much data you kept.

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

Zabbix

Free
  • ZabbixFree
    • No device, node or metric limits
    • Full feature set with no paid edition of the software
    • AGPLv3 from version 7.0 onward
  • Zabbix Technical Support$undefined/year
    • Tiered subscriptions with defined response times
    • Access to Zabbix engineers for configuration and performance issues
    • Bug fix priority and backports

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 Zabbix if

  • You need agent and agentless collection.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Web.
  • You also want templates.
Zabbix review

Questions people ask

Is Eclipse Mosquitto or Zabbix better?
Neither clearly leads. Eclipse Mosquitto starts at Free and Zabbix at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Eclipse Mosquitto or Zabbix?
Eclipse Mosquitto starts at Free and Zabbix at Free.
Does Eclipse Mosquitto or Zabbix run on more platforms?
Eclipse Mosquitto runs on Linux, Windows, macOS, Docker. Zabbix runs on Linux, Docker, Kubernetes, Web.
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 Zabbix is typically brought in for.
What can Eclipse Mosquitto do that Zabbix cannot?
Eclipse Mosquitto covers MQTT 5.0 support, Very small footprint, Bridging, WebSockets listener. Zabbix covers Agent and agentless collection, Templates, Low-level discovery, Distributed proxies.

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.

Zabbix: Is Zabbix genuinely free for commercial use?

The software has no licence fee at any scale. From version 7.0 it is AGPLv3, so offering it as a network service to third parties carries source distribution obligations.

Eclipse Mosquitto: What licence is it?

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

Zabbix: What is the real cost of running it?

Database administration and the person who tunes it. Budget for PostgreSQL with TimescaleDB and someone who owns the retention policy.

Eclipse Mosquitto: How many clients can it handle?

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

Zabbix: How does it compare to a commercial per-device tool?

It removes the licence line entirely and adds an operations line. Below a few hundred devices the commercial tool is often cheaper in total; above that Zabbix wins clearly.

Eclipse Mosquitto: Does it support MQTT 5?

Yes, along with 3.1.1 and 3.1.

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