Overview

Checkmk covers web, mail and database servers with more than 2,000 smart checks, automatic discovery and network mapping. Native agents, agentless checks and API-based checks let teams choose an approach for each system rather than relying on a single collection method. That is useful in mixed environments, although the range of methods and deployment choices will matter less to teams with a narrow monitoring scope.

A single instance can monitor thousands of servers, and distributed monitoring supports horizontal scaling. Checkmk can run on customer hardware or in virtualized environments, with packages for major Linux distributions, Docker and a Virtual Appliance. These options make it suitable for organizations that want control over deployment as well as room to grow; Community, by contrast, is designed for small infrastructures and scales to approximately 100 hosts.

Key features

Flexible checks: Native agents cover Windows, Linux and other operating systems. Agentless SNMP and TCP/UDP monitoring help where installing an agent is unsuitable, while API-based checks using HTTP/XML, SSH or TELNET provide additional routes into systems.
Cloud monitoring: AWS, Azure and Google Cloud Platform coverage includes automatic detection of cloud components and Quick Setup. This makes Checkmk a plausible option for teams combining public cloud with data-center or other infrastructure.
Integrations and automation: Community includes more than 2,000 built-in integrations, with REST APIs and custom automation scripts also supported. That breadth can reduce the need to build basic integrations from scratch, while the ability to script leaves room to adapt monitoring to local workflows.
Secure remote monitoring: Ultimate provides zero-inbound, fully encrypted monitoring through push agents and Checkmk Relay. That is a meaningful choice for environments where inbound access is undesirable, but this capability is specifically tied to Ultimate.
Service and VM monitoring: Checkmk supports both, alongside infrastructure monitoring. Metrics retention is custom, so buyers should consider their own retention requirements when assessing fit.

Pricing

Checkmk uses a freemium model. Community is free forever at no cost, with 2,000+ pre-built integrations, support from the community and coverage for up to approximately 100 hosts. It is the natural starting point for small environments that can work without professional support; its host scope makes it a poor fit for larger estates.

Pro costs 275.00 USD per month, billed annually, from $275/month. It covers the equivalent of approximately 3,000 services, with pricing as low as ~$2.75/host per month and professional support for 8h x 5d. This is the paid option for teams that need a larger service scope and business-hours support. Ultimate costs 400.00 USD per month, billed annually, from $400/month; it covers the equivalent of approximately 3,000 services, can be as low as ~$4.00/host per month, and includes 10h x 5d professional support, upgradeable to 24h x 5d. Its higher price is most defensible when that support window or its zero-inbound encrypted monitoring matters.

Cloud costs 290.00 USD per month with monthly billing, at approximately $8.70/host per month. Its stated scope is 1K–50K services, with 99.5% availability; at 1 host to approximately 30 services, buyers should match the service allowance to their estate rather than compare host counts alone. Synthetic Monitoring is 0.00 USD per month, billed annually, at $0.00/test with 3 free tests, and is available with Pro and Ultimate.

The pricing note gives paid plans from €190/mo (annual) and a 30-day trial. Individual plan prices use USD, so the stated euro starting point and the USD plan figures are not directly interchangeable.

Platforms

Checkmk supports API, Linux, macOS, self-hosted, web and Windows. Its hybrid deployment model, multiple operating-system coverage and agentless monitoring support make it relevant to teams spanning managed infrastructure and systems where agents are not an option.

Who it's for

Checkmk is best suited to infrastructure teams that need to monitor a mix of servers, cloud components, networks, containers and services, and that value a choice between agents, agentless checks and APIs. Community suits a small estate that can rely on community support. Growing or larger environments can consider paid plans, with Pro or Ultimate for annual billing and professional support, or Cloud for monthly billing and its stated service range. Teams looking for a narrowly scoped tool, or a free edition for substantially more than approximately 100 hosts, should look elsewhere.

Pros and cons

Pro: More than 2,000 checks and integrations, plus multiple collection methods, give mixed environments broad monitoring coverage.
Pro: One instance can monitor thousands of servers, with distributed monitoring for horizontal scaling as infrastructure grows.
Pro: Customer-hardware, virtualized, Docker and Virtual Appliance deployment options give teams meaningful control over where Checkmk runs.
Con: Community is limited to small infrastructures and approximately 100 hosts, so larger deployments need a paid plan.
Con: Plan prices are expressed in USD while the pricing note starts at €190/mo (annual), complicating direct price comparisons.
Con: Professional support is tied to paid tiers, and the stated support windows differ between Pro and Ultimate.

Alternatives

For teams comparing monitoring categories, see Infrastructure Monitoring, Cloud Monitoring, Container Monitoring, Metrics Monitoring Tools, and Hardware Monitoring Software. Managed service providers can also browse Managed Service Provider Software.

Breeze is worth considering for a free self-hosted option with unlimited devices and all 64 modules. ManageEngine MSP Central may suit buyers seeking a per-device network monitoring and management plan. Atera, Pulseway, Site24x7 MSP, Liongard, SuperOps and Hudu are other alternatives to compare.

Verdict

Choose Checkmk if you need broad monitoring across mixed infrastructure, want a choice of collection methods and deployment models, and expect to grow beyond a small estate. Its free Community edition makes a small deployment accessible, while paid tiers add defined service scopes and professional support. Look elsewhere if you need a free plan beyond approximately 100 hosts or need a single, directly comparable price across its plan options.

	Checkmk	siomon
Free plan	Yes
Free trial	Yes
Paid from	$275/mo
Open source	Yes
Platforms	Android, api, iOS, Linux, macOS, self-hosted, Web, Windows	Linux
Free plan	Yes	Yes
VM monitoring	Yes
Service monitoring	Yes
Metrics retention	custom
Deployment model	hybrid
OS coverage	multiple
Agentless monitoring	Yes
Supported platforms		linux

Checkmk vs siomon

Checkmk

siomon