What is Checkmk used for?

Checkmk is a scalable IT monitoring system for infrastructure and applications across physical, virtual, container, and cloud environments, with a free open-source Community edition. It is a good fit for monitoring mixed physical and virtual infrastructure, and managed service providers monitoring customer systems.

Is Checkmk open source?

Yes. Checkmk is open source under the GPL-2.0 licence. Its source code is on GitHub at Checkmk/checkmk and is written mainly in Python.

Yes. Checkmk is open source, so the software itself is free to use. Paid plans are also available, starting at €190 per month.

Can I self-host Checkmk?

Yes. Checkmk can be self-hosted on your own server or infrastructure.

What is Checkmk an alternative to?

Checkmk is an open-source alternative to Datadog, PRTG Network Monitor, SolarWinds Observability and Site24x7. Other open-source alternatives to Datadog include Zabbix, Nagios Core and Icinga 2.

Is Checkmk actively maintained?

Yes. The most recent commit to Checkmk was on 2 October 2026. The project has 2.4k stars on GitHub.

Checkmk: open-source alternative to Datadog

About Checkmk

Checkmk is a comprehensive IT monitoring system designed for scalability, flexibility, and low resource consumption. It monitors infrastructure and applications across physical servers, virtual machines, containers, and cloud environments. It is written mainly in Python.

The Checkmk Community edition is free and open source under the GNU GPL v2. It includes the core monitoring engine, a web-based interface, agent-based and agentless monitoring, and support for hundreds of official and community plugins, and is suited to smaller environments with basic automation, dashboarding, and support needs. Commercial editions extend it: Pro adds distributed monitoring, built-in dashboards, automated agent management, enterprise integrations such as LDAP and REST APIs, and professional support, and Ultimate adds enhanced monitoring for dynamic cloud-native environments such as Kubernetes, AWS, Azure, and GCP.

The website provides documentation, releases, and discussion forums, and a demo of the Pro edition can be downloaded for evaluation. Checkmk suits IT operations teams and managed service providers that want a single tool for servers, networks, and applications.

Key features

Agent-based and agentless monitoring
Web-based interface
Hundreds of official and community plugins
Distributed monitoring in the commercial Pro edition
Cloud-native monitoring in the Ultimate edition
Low resource consumption design

Good fit for

→Monitoring mixed physical and virtual infrastructure
→Managed service providers monitoring customer systems

Built with: Python
Tags: monitoring; infrastructure; it-operations; network-monitoring; alerting; python; self-hosted; observability

Checkmk: questions and answers

What is Checkmk used for?: Checkmk is a scalable IT monitoring system for infrastructure and applications across physical, virtual, container, and cloud environments, with a free open-source Community edition. It is a good fit for monitoring mixed physical and virtual infrastructure, and managed service providers monitoring customer systems.
Is Checkmk open source?: Yes. Checkmk is open source under the GPL-2.0 licence. Its source code is on GitHub at Checkmk/checkmk and is written mainly in Python.
Is Checkmk free?: Yes. Checkmk is open source, so the software itself is free to use. Paid plans are also available, starting at €190 per month.
Can I self-host Checkmk?: Yes. Checkmk can be self-hosted on your own server or infrastructure.
What is Checkmk an alternative to?: Checkmk is an open-source alternative to Datadog, PRTG Network Monitor, SolarWinds Observability and Site24x7. Other open-source alternatives to Datadog include Zabbix, Nagios Core and Icinga 2.
Is Checkmk actively maintained?: Yes. The most recent commit to Checkmk was on 2 October 2026. The project has 2.4k stars on GitHub.