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Head-to-head · Server Monitoring

Checkmk vs Nagios Core

  • Updated Oct 2026
  • Both researched from official sources
  • 2 checks side by side
Higher score Checkmk #1 in Server Monitoring 9.4/10 Free plan · 30-day trial Free planFree trial✓ 0 of 3 features Visit Checkmk
Nagios Core #8 in Server Monitoring 8.7/10 Free plan Free plan✓ 1 of 3 features Visit Nagios Core

Checkmk leads on 0 checks, Nagios Core on 0, and 2 are even. Who comes out ahead on the 2 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreCheckmk · 9.4/10
  • Free planboth
  • Free trialonly Checkmk
  • Most featuresNagios Core · 1 of 3

Checkmk scores higher on our rubric for server monitoring: 9.4 against 8.7 out of 10; our editors rank them #1 and #8.

Checkmk is the better fit for enterprise infrastructure teams. Nagios Core is the better fit for free extensible monitoring with a large ecosystem.

  • Checkmk fits best

    Enterprise infrastructure teams

  • Nagios Core fits best

    Free extensible monitoring with a large ecosystem

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Side by side

Feature Checkmk 9.4/10 Visit ↗ Nagios Core 8.7/10 Visit ↗
At a glance
Editor score 9.4 8.7
Ranking #1 in Server Monitoring #8 in Server Monitoring
Best for Enterprise infrastructure teams Free extensible monitoring with a large ecosystem
Pricing model Free plan + paid Free
Starting price €190/mo Free plan
Free plan ✓ ✓
Free trial 30 days —
Deployment Cloud, Self-hosted Self-hosted
Platforms Web, Linux, Windows Linux
Support Community, Tickets, Docs Community, Docs
Integrations 2,000+ integrations 6 integrations
Built for Small business, Mid-market, Enterprise Small business, Mid-market, Enterprise
Features Checkmk 0/3 · Nagios Core 1/3
Server auto-discovery Not checked yet Not checked yet
Process monitoring Not checked yet ✓ (best)
Container monitoring Not checked yet Not checked yet
Specs
Included hosts Not checked yet Not checked yet
Metric retention Not checked yet Not checked yet
Monitoring method Not checked yet Hybrid
Supported operating systems Not checked yet Linux, Unix, Windows
Our review
Pros
  • Monitors servers, networks, storage, cloud, Kubernetes, and VMs
  • Free open-source Community edition with 2000+ pre-built integrations
  • Supports agents, SNMP, APIs, OpenTelemetry, and distributed monitoring
  • Free, GPL-licensed, self-hosted monitoring engine
  • Plugin architecture supports custom checks and metrics
  • Integrates with Grafana, Prometheus, Slack, and ServiceNow
Cons
  • Paid plans start at €190 per month with annual billing
  • Community edition scales to approximately 100 hosts
  • Professional support is limited to paid Pro and Ultimate plans
  • Configuration relies mainly on text files and command-line workflows
  • The platform listing is limited to Linux
  • It lacks a server auto-discovery feature
Our verdict

Checkmk is an infrastructure monitoring and observability platform for IT teams managing on-premises, cloud, hybrid, and containerized environments. It discovers hosts and services, collects status and performance data, and provides…

Read the review →

Nagios Core is a free, GPL-licensed, self-hosted monitoring engine for IT infrastructure. It monitors servers, workstations, network devices, websites, applications, services, and custom metrics through a plugin-based architecture. Its…

Read the review →
  1. CheckmkServer Monitoring 9.4Free plan · 30-day trial
  2. Nagios CoreServer Monitoring 8.7Free plan

Strengths and trade-offs

  • Checkmk — where it wins

    • Monitors servers, networks, storage, cloud, Kubernetes, and VMs
    • Free open-source Community edition with 2000+ pre-built integrations
    • Supports agents, SNMP, APIs, OpenTelemetry, and distributed monitoring

    Where it doesn't

    • Paid plans start at €190 per month with annual billing
    • Community edition scales to approximately 100 hosts
    • Professional support is limited to paid Pro and Ultimate plans

  • Nagios Core — where it wins

    • Free, GPL-licensed, self-hosted monitoring engine
    • Plugin architecture supports custom checks and metrics
    • Integrates with Grafana, Prometheus, Slack, and ServiceNow

    Where it doesn't

    • Configuration relies mainly on text files and command-line workflows
    • The platform listing is limited to Linux
    • It lacks a server auto-discovery feature

More comparisons

All server monitoring comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update