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Networking · head to head

Icinga vs PRTG Network Monitor

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
PRTG Network Monitor logo

PRTG Network Monitor

Networking

Infrastructure monitoring licensed by sensor count, not by device, which changes what a licence actually covers

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Icinga has a free tier, so it costs nothing to try first.
  • 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; PRTG Network Monitor licensing by sensor rather than device means the real cost per device is unpredictable until sensor density is measured; a small network of complex devices can need a much larger tier than device count alone suggests
  • They diverge on capability: Icinga covers Forever Free core, PRTG Network Monitor covers Sensor-based monitoring.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Icinga and PRTG Network Monitor actually diverge.

Attributes where Icinga and PRTG Network Monitor differ
AttributeIcingaPRTG Network Monitor
Starting priceFreeOn request
Pricing modelOpen source core, with paid repository, module and support subscriptions sold separatelyPer sensor tier, billed monthly on an annual contract
Free tierYesNo
PlatformsLinux, WebWindows, Web, iOS, Android

Identical on both: 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 Icinga

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

Only in PRTG Network Monitor

  • Sensor-based monitoring
  • Auto-discovery
  • Multiple monitoring technologies
  • Maps and dashboards
  • Cloud and hybrid deployment

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 PRTG Network Monitor
  • An organisation on RHEL or SLES that wants officially packaged Icinga builds via the repository subscription rather than building from sourcenot PRTG Network Monitor
  • A team wanting an SLA-backed vendor support relationship rather than relying on community forums for a production monitoring systemnot PRTG Network Monitor
  • A company already invested in Prometheus and Grafana wanting to add host and service-level alerting from a compatible open source toolnot PRTG Network Monitor

PRTG Network Monitor

  • An IT team wanting network, server and application monitoring in one product rather than assembling separate open source toolsnot Icinga
  • An organisation that wants a Windows-installable on-premises monitoring server with a polished UI out of the boxnot Icinga
  • A team sizing a monitoring purchase that needs to calculate sensor density per device carefully before committing to a tiernot Icinga
  • A company wanting hybrid on-premises and cloud monitoring from the same licence and dashboardnot 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

PRTG Network Monitor

  • Licensing by sensor rather than device means the real cost per device is unpredictable until sensor density is measured; a small network of complex devices can need a much larger tier than device count alone suggests
  • Different PRTG licence sizes cannot be combined on one server, so outgrowing a tier means a step change to the next tier rather than a smooth incremental add
  • It requires a Windows server for on-premises deployment, which is an added infrastructure and patching burden compared with a Linux-native open source alternative
  • Pricing is materially higher than open source options like Icinga or LibreNMS for comparable core monitoring capability, and the premium is for polish and support rather than unique functionality
  • The free tier (100 sensors) is limited enough that most real deployments quickly need a paid tier, so it functions more as a trial than a genuinely usable free offering
  • Custom sensor scripting and advanced configuration still require real monitoring expertise; the polished UI does not remove the underlying complexity of correctly instrumenting a large network

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

PRTG Network Monitor

On request
  • PRTG 500$200/month
    • Up to 500 sensors
  • PRTG 1000$358/month
    • Up to 1,000 sensors
  • PRTG 2500$742/month
    • Up to 2,500 sensors
  • PRTG 5000$1300/month
    • Up to 5,000 sensors

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 PRTG Network Monitor if

  • You need sensor-based monitoring.
  • You work on Windows, Web, iOS, Android.
  • You also want auto-discovery.
PRTG Network Monitor review

Questions people ask

Is Icinga or PRTG Network Monitor better?
Neither clearly leads. Icinga starts at Free and PRTG Network Monitor at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Icinga or PRTG Network Monitor?
Icinga has a free tier; the other does not. Paid plans start at Free for Icinga and On request for PRTG Network Monitor.
Does Icinga or PRTG Network Monitor run on more platforms?
Icinga runs on Linux, Web. PRTG Network Monitor runs on Windows, Web, iOS, Android.
Can I use Icinga for free?
Yes. Icinga has a free tier, so you can try it without paying. PRTG Network Monitor starts at On request.
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 PRTG Network Monitor is typically brought in for.
What can Icinga do that PRTG Network Monitor cannot?
Icinga covers Forever Free core, Clustering and HA, Icinga Web and API, Enterprise modules (paid). PRTG Network Monitor covers Sensor-based monitoring, Auto-discovery, Multiple monitoring technologies, Maps and dashboards.

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.

PRTG Network Monitor: Is PRTG licensed per device or per sensor?

Per sensor. Each individually monitored metric counts as one sensor, so a single device is typically several sensors.

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.

PRTG Network Monitor: Can I combine two PRTG licence tiers on one server?

No, Paessler states different license sizes cannot be combined on one PRTG installation.

Icinga: Is Icinga related to Nagios?

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

PRTG Network Monitor: Is there a free tier?

Yes, PRTG offers a free tier limited to 100 sensors, which most production networks will exceed quickly.

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