Free and open first
Best Server Monitoring in 2026
Use server monitoring tools to observe hosts, gather metrics and identify service problems. The list includes Linux, Windows, macOS, web, self-hosted and API-oriented choices.
- 38 apps
- Research read 23 Sept 2026
- How the order is worked out
- 1
- 2
Checkmk
Free plan Open source AndroidAPIiPhone+5Checkmk offers broad infrastructure coverage and several monitoring methods, with a free Community option for smaller environments.
- 3
Glances
Free plan Open source AndroidAPILinux+4Glances covers a broad set of system metrics and offers several ways to monitor remotely or export statistics. Check its Python requirement and optional dependency setup against the features you need.
- 4
Netdata
Free plan Open source AndroidAPIiPhone+5Netdata combines infrastructure metrics, logs, alerts, and troubleshooting across cloud and on-premises deployment options.
- 5
Beszel
Free plan APILinuxMac+3 - 6
Canonical Landscape
Free plan APILinuxSelf-hosted+1Landscape combines Ubuntu fleet administration, monitoring, and several deployment options.
- 7
Icinga
Free plan APILinuxSelf-hosted+2Icinga offers self-hosted monitoring with a free edition and options for distributed setups, certificate monitoring, and integrations.
- 8
eZ Server Monitor
Free plan LinuxSelf-hostedWeb - 9
ManageEngine OpManager
Free plan AndroidAPIiPhone+4OpManager brings infrastructure metrics, traffic analysis, alerts, and troubleshooting into one self-hosted product.
- 10
Nagios XI
Free plan APILinuxMac+3Nagios XI offers self-hosted monitoring, a limited free edition, and perpetual paid licenses priced by node count.
- 11
Monit
Free plan LinuxMacSelf-hostedMonit combines system checks, alerts, and process actions in a free self-hosted utility for Linux and macOS.
- 12
Munin
Free plan APILinuxSelf-hostedChoose Munin if you want free, self-hosted resource monitoring with graphing, a broad plugin ecosystem, and configurable alerts.
- 13
Naemon
Free plan LinuxSelf-hostedWeb - 14
Nagios Core
Free plan APILinuxSelf-hosted - 15
NetXMS
Free plan AndroidAPILinux+4NetXMS combines discovery, topology maps, protocol support, and distributed monitoring in an open-source solution.
- 16
openITCOCKPIT
Free plan APIiPhoneLinux+4openITCOCKPIT covers a broad range of infrastructure and application monitoring, with dashboards, reporting, and integrations.
- 17
OpsDash
Free plan APILinuxSelf-hosted+2 - 18
Paessler PRTG Network Monitor
Free plan AndroidAPIiPhone+5PRTG combines on-premises infrastructure monitoring with alerts, reports, dashboards, and an API. Check sensor needs and the single-license-per-server limit when choosing a plan.
- 19
Monitorix
Free plan LinuxSelf-hostedChoose Monitorix if you want a free, self-hosted tool for server, service, and hardware monitoring, with multihost graphs and configurable history.
- 20
Performance Co-Pilot
Free plan APILinuxMac+2Choose PCP if you need a free, self-hosted toolkit for collecting and analyzing performance data across multiple hosts.
- 21
Prometheus
Free plan LinuxMacSelf-hosted+2Prometheus provides a free monitoring and alerting toolkit with flexible metric collection and querying. Its stated accuracy limitation makes it unsuitable for per-request billing workloads.
- 22
Sensu Go
Free plan APILinuxMac+3Sensu Go combines event processing, infrastructure discovery, alerting, and remediation in a self-hosted monitoring product.
- 23
Site24x7 Server Monitoring
Free plan AndroidAPIiPhone+4Site24x7 Server Monitoring brings server metrics, agent and agentless monitoring, and integrations into one platform.
- 24
Watchflare
Free plan LinuxMacSelf-hosted+1Watchflare combines host monitoring, package inventory, and configurable alerts in a self-hosted system.
- 25
WhatsUp Gold
Free plan APISelf-hostedWeb+1WhatsUp Gold brings network mapping, device and application monitoring, traffic analysis and alerts into one product.
#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price
Compare free plans, trial periods and open-source licences before choosing. Review retention periods, monitoring approaches, supported operating systems, automatic server discovery, process and container coverage, host allowances and paid costs.
Questions
Are free server monitoring tools available?
Yes. Free plans appear among the listed tools, including Beszel, Cockpit Machines, Glances and Icinga.
Which server monitoring tools are open source?
The list identifies Beszel and eZ Server Monitor as open source. Check the licence before reading or changing code.
Which tools have a free trial?
Trial lengths listed include 15 days for LogicMonitor, 21 for eG Enterprise, 30 for BizTalk360, Canonical Landscape, Checkmk and FrameFlow, and 60 for Icinga.
What should I compare between monitoring tools?
Review free-plan terms, paid costs, host allowances, metric retention, monitoring approach, operating-system support, automatic discovery, process monitoring and container monitoring.
Which platforms are covered?
Linux, Windows, macOS, web, self-hosted and API-based tools all appear in the list. Check the supported operating systems for a specific tool.