Softwr

Networking · head to head

Icinga vs NATS

Icinga logo

Icinga

Networking

Open source infrastructure monitoring, free at its core, with paid support and modules sold separately by Icinga GmbH

From
Free
Rated
-
Full reviewWebsite
NATS logo

NATS

Databases

High-performance messaging system for cloud-native applications

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Icinga the free core has no vendor SLA, so production incidents are supported through community channels unless a paid support subscription is purchased; NATS core NATS has no persistence at all, so messages are lost if no subscriber is listening
  • They diverge on capability: Icinga covers Forever Free core, NATS covers Very low latency.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Icinga and NATS actually diverge.

Attributes where Icinga and NATS differ
AttributeIcingaNATS
Pricing modelOpen source core, with paid repository, module and support subscriptions sold separatelyOpen source, no licence fee
PlatformsLinux, WebLinux, macOS, Windows, Docker, Kubernetes
CategoryNetworkingDatabases

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 Icinga

  • Forever Free core
  • Clustering and HA
  • Icinga Web and API
  • Enterprise modules (paid)
  • Integration ecosystem

Only in NATS

  • Very low latency
  • JetStream
  • Single binary
  • Request-reply

What people use each for

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

Icinga

  • An IT team wanting unlimited-scale open source monitoring with no per-host licence fee, running standard Linux distributionsnot NATS
  • An organisation on RHEL or SLES that wants officially packaged Icinga builds via the repository subscription rather than building from sourcenot NATS
  • A team wanting an SLA-backed vendor support relationship rather than relying on community forums for a production monitoring systemnot NATS
  • A company already invested in Prometheus and Grafana wanting to add host and service-level alerting from a compatible open source toolnot NATS

NATS

  • Service-to-service messaging where latency is the binding constraintnot Icinga
  • Edge and IoT messaging where a lightweight broker mattersnot Icinga
  • Replacing a heavier broker when the workload does not need its guaranteesnot Icinga

Where each one falls short

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

Icinga

  • The free core has no vendor SLA, so production incidents are supported through community channels unless a paid support subscription is purchased
  • Repository access for enterprise Linux distributions like RHEL and SLES is not free, so organisations standardised on those distributions face a real recurring cost most open source monitoring buyers do not expect
  • Enterprise modules are gated behind a separate module subscription, so some functionality demonstrated in marketing material is not part of the free core
  • Self-hosting and operating Icinga requires real Linux and monitoring expertise that a commercial SaaS tool would otherwise absorb, so total cost of ownership includes staff time not captured in the licence price
  • Pricing for the paid subscriptions varies by geographic region and is not published as a single global rate card, complicating budgeting for multinational organisations
  • The web interface and configuration language, while capable, are less immediately polished than a fully commercial tool like PRTG, and initial setup takes longer to reach a usable state

NATS

  • Core NATS has no persistence at all, so messages are lost if no subscriber is listening
  • JetStream adds the durability but also the operational complexity NATS is chosen to avoid
  • A much smaller ecosystem than Kafka or RabbitMQ, with fewer connectors and integrations
  • Fewer people know it, so hiring and existing organisational knowledge favour the alternatives

Pricing, plan by plan

Icinga

Free
  • IcingaFree
    • Unlimited hosts and services
    • Clustering and API
    • Community support
  • Support Subscription$undefined/year
    • Professional support (8x5 or 24/7)
    • Includes module and repository subscriptions

NATS

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

Which should you pick?

Choose Icinga if

  • You need forever free core.
  • You want to start without paying.
  • You work on Linux, Web.
  • You also want clustering and ha.
Icinga review

Choose NATS if

  • You need very low latency.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Kubernetes.
  • You also want jetstream.
NATS review

Questions people ask

Is Icinga or NATS better?
Neither clearly leads. Icinga starts at Free and NATS at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Icinga or NATS?
Icinga starts at Free and NATS at Free.
Does Icinga or NATS run on more platforms?
Icinga runs on Linux, Web. NATS runs on Linux, macOS, Windows, Docker, Kubernetes.
Can I use Icinga for free?
Both have a free tier, so you can try either at no cost before committing.
What is Icinga best used for?
Icinga is most often used for an it team wanting unlimited-scale open source monitoring with no per-host licence fee, running standard linux distributions, an organisation on rhel or sles that wants officially packaged icinga builds via the repository subscription rather than building from source, a team wanting an sla-backed vendor support relationship rather than relying on community forums for a production monitoring system, a company already invested in prometheus and grafana wanting to add host and service-level alerting from a compatible open source tool. Of those, an it team wanting unlimited-scale open source monitoring with no per-host licence fee, running standard linux distributions and an organisation on rhel or sles that wants officially packaged icinga builds via the repository subscription rather than building from source are not what NATS is typically brought in for.
What can Icinga do that NATS cannot?
Icinga covers Forever Free core, Clustering and HA, Icinga Web and API, Enterprise modules (paid). NATS covers Very low latency, JetStream, Single binary, Request-reply.

Answered from the vendors’ own pages

Icinga: Is Icinga free to run in production?

Yes, the core platform has no licence fee and no limit on hosts or services monitored.

NATS: Is NATS free?

Yes, open source and CNCF-graduated. Synadia sells a managed service.

Icinga: What do the paid subscriptions actually add?

A repository subscription provides packages for certain enterprise Linux distributions, a module subscription unlocks enterprise-only add-on modules, and a support subscription bundles both with professional support.

NATS: Does NATS persist messages?

Core NATS does not — it is fire-and-forget. JetStream adds persistence, streaming and replay when you need them.

Icinga: Is Icinga related to Nagios?

Yes, it originated as a fork of Nagios but has since diverged into an independently developed platform.

NATS: NATS or Kafka?

NATS is far lighter and lower latency, and much simpler to run. Kafka is the answer when you need a durable replayable log and a large connector ecosystem.

Share

Related pages

More on Icinga

More on NATS

Keep looking

Other head to heads