When is the free Checkmk Community edition enough?
If your estate is small, the free Community edition is usually enough. Checkmk describes Community as free, open-source monitoring for small infrastructures, easily scalable up to about 100 hosts, and it carries no licence fee. Paid editions become necessary once you outgrow that host count, need distributed monitoring across remote sites, want vendor support, or must separate monitoring for several customers or business units. Before you decide, count hosts and services honestly, including network devices and cloud instances that tend to be forgotten, and confirm the count against the thresholds in the Checkmk editions page.
Community is built on the Nagios core, which is a long-established and well-understood engine. Its GPL-2.0 licence on the Checkmk source repository means you can inspect and modify the code, and its zero licence cost is a real advantage for a team with spare engineering time and no need for a support contract. The trade-off is that you carry the operating work yourself, including upgrades, backups and troubleshooting, and you have no vendor support channel. Ask whether your team can absorb those tasks within its normal change window. If the answer is no, the cost of a paid edition may be lower than the cost of unplanned downtime.
Choose Pro when the constraints are scale, distribution and support rather than feature depth. Pro adds advanced analytics and reporting, automation, distributed monitoring and 8x5 support, and it creates new sites on the Checkmk Micro Core by default. Choose Ultimate only when you need multi-tenancy, push-mode agents with automatic host registration, or automated mass rollouts. Confirm the current list prices on the editions page, since they are billed annually, and ask your vendor to quote your exact host count and add-ons such as Synthetic Monitoring, which is available only with Pro and Ultimate.
Which Checkmk features are paid and which are free?
This table sorts the documented Checkmk capabilities across Community, Pro and Ultimate. Read a cell marked as a confirmation item as a gap in the public sources, not a confirmed absence, and check it with Checkmk before you build a plan on it. The main takeaway: distributed monitoring and 8x5 support point to Pro, while multi-tenancy, mass rollouts and push-mode agents point to Ultimate.
| Feature | Community | Pro | Ultimate |
|---|---|---|---|
| Monitoring core | Nagios core, the free default for self-hosted sites | Checkmk Micro Core for new sites, Nagios core optional for migration | Checkmk Micro Core for new sites, Nagios core optional for migration |
| Published price (billed annually) | Free and open source, scaled to about 100 hosts | 190 euros per month, per the Checkmk editions page | 275 euros per month, per the Checkmk editions page |
| Analytics, reporting and automation | Not listed in the editions page; confirm with Checkmk | Advanced analytics, reporting and automation | Includes the Pro set plus full-stack observability |
| Distributed monitoring and support | Not listed; confirm before planning remote sites | Distributed monitoring and 8x5 support | Confirm the support tier and distributed monitoring scope with Checkmk |
| Multi-tenancy, security compliance and mass rollouts | Not listed; confirm if you need tenant separation | Not listed in the Pro description; confirm if needed | Multi-tenancy, advanced security compliance and automated mass rollouts |
| Push-mode agents and automatic host registration | Not documented; confirm before relying on it | Not documented for Pro; confirm before relying on it | Documented Ultimate feature per the Checkmk setup guide |
| Synthetic Monitoring | Not available as an add-on | Add-on available | Add-on available |
| Installation packaging | Linux packages or Docker images | Linux packages, Docker images, and virtual or physical appliances | Linux packages, Docker images, and virtual or physical appliances |
How licensing and support differ by edition
Checkmk's licensing story is simpler than most commercial monitoring products: the source is open, and the paid editions change what you receive around it. The four cards below separate what is licensed, what support you buy, what update terms you should confirm, and which monitoring core each edition runs.
Licence of the source code
The Checkmk source repository on GitHub is licensed under GPL-2.0, and Checkmk describes Community as free, 100 percent open-source software. The license applies to the code in the repository, so a team running Community can read, audit and modify it under those terms. Before you build on it, confirm with Checkmk GmbH which licence terms apply to any commercial-only components you plan to rely on, since the paid editions are sold as products rather than as the open repository alone.
Community support model
Community is free to download and run, and it is designed for small infrastructures scaling to about 100 hosts. Vendor support is not part of the free edition, so problems are handled through community channels and your own staff. If your monitoring must answer to an on-call rota or a service level, treat the free edition as a platform you operate yourself and budget the internal time for it.
Pro support and 8x5 coverage
Pro adds vendor support, and the published support window is 8x5, meaning coverage during business hours on weekdays. Pro also bundles distributed monitoring and advanced reporting, so support matters most for remote sites and reporting pipelines. If your operations run outside those hours, ask Checkmk to confirm in writing what escalation paths and response targets apply, and whether an upgrade to a higher support tier is available.
Ultimate support and update terms
Ultimate adds multi-tenancy, full-stack observability and automated mass rollouts, which raise the stakes of an outage or a bad update. The supplied material does not state Ultimate's support window or how long each release line receives patches, so do not assume it matches Pro. Ask Checkmk for the support hours, response targets, patch policy for each release, and whether updates are included in the monthly price or billed separately.
Monitoring core by edition
Community runs on the Nagios core, while the commercial editions create new sites with the Checkmk Micro Core (CMC) by default. The Nagios core remains available in the paid editions as an optional choice for migration. If you run existing Nagios-style configuration, confirm how your checks, plugins and notification scripts behave on CMC before you commit to an edition, because the core you run determines the scale and migration work that follows.
What the Checkmk Micro Core changes for Pro and Ultimate sites
The core you run is the most consequential difference between the editions for an existing Checkmk deployment. According to the Checkmk docs, the commercial editions create new sites with the Checkmk Micro Core (CMC) by default, while Checkmk Community is built on the Nagios core. The commercial editions keep Nagios available only as an optional core, intended for migration. If you are buying Pro or Ultimate for a new site, expect CMC. If you are migrating an existing Community site, plan for a period in which the Nagios core is used as a stepping stone rather than assuming the new core is active from day one.
The Checkmk docs cite benchmark figures from the vendor: the CMC executed more than 600,000 checks per minute on a desktop Core i7, and it loaded a configuration of 20,000 hosts and 600,000 services in about half a second. These numbers describe a synthetic test on specific hardware. They do not tell you how your environment will behave. Before you size a Pro or Ultimate site, build a test instance, import a representative sample of your hosts and services, and measure check throughput and configuration reload time with the check mix you actually run, including any slow custom plugins and remote checks. Ask your Checkmk contact to confirm which core a quoted site will use and which migration path applies to your current Community installation.
Note that the core choice is independent of the edition you pick, so a benchmark gap should not be read as an argument for one edition over another. The practical question is whether the CMC behaves well under your load and whether your existing checks, notifications and integrations work on it. Document any incompatibilities during the test phase and include them in your migration plan, so the decision rests on evidence from your own estate.
Which edition fits which team?
A single team monitoring under about 100 hosts usually has one or two administrators who also own patching, backups and the monitoring server itself. Community fits this profile well. The Checkmk editions page describes it as free, open-source monitoring for small infrastructures, easily scalable up to about 100 hosts. It installs from Linux packages or as a Docker container image, and it runs on the Nagios core, with the Checkmk source published under GPL-2.0.
- License cost: Community has no subscription line item. Your costs are the server, staff time and any outside help you choose to buy.
- Host ceiling: The free edition is positioned for about 100 hosts. If your inventory is trending toward that figure, plan the move to a paid edition before you reach it.
- Core choice: Community stays on the Nagios core, while the commercial editions create new sites with the Checkmk Micro Core by default. Confirm the Nagios core handles your check volume and polling interval.
- Support: No vendor support tier is listed for Community. If outages must be answered within a defined window, budget for a paid edition or a third-party contract.
Recheck your host count every few months, not only at purchase, and confirm whether your team can absorb upgrade and patch work without a vendor escalation path.
An estate that has outgrown one monitoring server, or that spans several networks or data centers, is the usual case for Pro. The editions page lists Pro from 190 euros per month, billed annually. It adds advanced analytics and reporting, automation, distributed monitoring and 8x5 support. Pro does not list multi-tenancy, push agents or automated mass rollouts, so if you need those, Pro alone will not cover the requirement.
- Distributed monitoring: Remote sites can be monitored from a central view, which suits environments where a single server cannot reach every network segment.
- Vendor support: 8x5 support covers business hours. If your incidents happen overnight, confirm whether a different support window is available before you sign.
- Core and migration: New sites use the Checkmk Micro Core by default. Ask how existing Nagios-based configurations move over and what testing the migration requires.
- Reporting and automation: Advanced analytics, reporting and automation help when managers or auditors expect regular output from the monitoring system.
- Add-ons: Synthetic Monitoring is available with Pro and Ultimate only, so price it as a separate decision.
Pro is not automatically the right choice for every mid-size estate. If your team is experienced, your outages can wait for business hours and you do not need vendor escalation, Community may still be the better answer. Confirm with Checkmk how the annual billing term affects a mid-year change in host count.
Ultimate is worth evaluating when several teams, business units or customers need separated views, or when hosts are created and removed too often for manual registration. The editions page lists Ultimate from 275 euros per month, billed annually, and adds full-stack observability, multi-tenancy, advanced security compliance and automated mass rollouts. Push-mode agents and automatic host registration are Ultimate features, according to the setup guide.
- Multi-tenancy: Separate customers or internal business units can see only their own hosts, which is the core need for a managed service provider.
- Push agents: Hosts can report outward to the monitoring server, which can reduce inbound firewall rules for hosts in segmented or changing networks. Confirm the network model in your own environment.
- Automatic registration and mass rollouts: These help when provisioning is frequent. Measure your current manual effort before attributing savings to the edition.
- Security compliance checks: Advanced security compliance is listed as a feature. Map its checks against your framework's control requirements before you rely on it for evidence.
- Appliances: Virtual and physical appliances are available only for commercial editions, which can simplify deployment for some teams.
If you have one team and no tenancy or push-agent need, the higher price buys little you will use. Ask Checkmk what the subscription is counted against, such as hosts, sites or services, and get that basis in writing with the quote.
What each Checkmk edition costs to run
This table separates the published licence fees from the costs you carry yourself, such as hardware, staff time and upgrades. Read the licence row as the only fixed number, then use the other rows to build a total for your own environment. Community has no licence fee, but it is not free to run.
| Cost component | Community (free, GPL) | Pro and Ultimate (paid) |
|---|---|---|
| Licence fee | No licence fee (free and open source per the Checkmk editions page) | Pro from 190 euros per month and Ultimate from 275 euros per month, both billed annually (Checkmk editions page) |
| Server hardware or VM | You provide the host or VM; Community is designed for small infrastructures, up to about 100 hosts | You provide the host or VM; sizing grows with host and service count, and distributed sites add more servers |
| Staff time to run the monitoring site | Your team installs, configures, patches and tunes the site with no vendor-included support | Same operating work, plus any support or onboarding you buy; confirm the response terms in writing |
| Upgrades and patching | Done by your team on the release cadence you choose | Same work, with commercial editions creating sites on the Checkmk Micro Core by default; plan migration checks when moving editions |
| Add-ons and features | Not available as paid add-ons | Synthetic Monitoring is an add-on for Pro and Ultimate; confirm its price with Checkmk |
| Support | Community forums and documentation only | Pro includes 8x5 support per the Checkmk editions page; Ultimate support level should be confirmed with Checkmk |
| Partner or implementation fees | Only if you hire a partner for design or rollout | Only if you hire a partner; DeployOpen does not publish prices and quotes follow from written scope |
How to move from Community to Pro or Ultimate
This sequence turns a Community deployment into a commercial Checkmk environment without losing monitoring coverage, leaving you with a documented, tested site and a known fallback if the subscription changes.
Confirm the edition you need
Before anything changes, list the features that justify the move: distributed monitoring and 8x5 support for Pro, or multi-tenancy, push-mode agents, automatic host registration and automated mass rollouts for Ultimate. Ask Checkmk GmbH or your reseller to confirm which edition includes each feature you need, and get the current monthly price in writing, billed annually as published on the editions page. Your output is a signed-off edition decision with a named owner and a written quote.
Plan the new commercial site
Commercial editions create new sites with the Checkmk Micro Core by default, so you build a new site rather than upgrading the Community site in place. Inventory your current hosts, services, notification rules and custom checks, and confirm with Checkmk which Community features map to the commercial edition. Ask whether any of your Community setup depends on Nagios-specific behavior. Your output is a written migration plan that names the target host, the installation method, and who approves the cutover.
Install the commercial site alongside Community
Install the commercial edition on a separate site, using one of the supported Linux packages or a Docker image if your deployment uses containers, and confirm that the commercial package is available for your operating system. Keep the Community site running during this stage so monitoring is never dark. Your output is a running commercial site with its own admin account, reachable from your network, and a record of the installed version.
Migrate from Nagios core where configuration depends on it
Only if your existing configuration relies on the Nagios core, confirm with Checkmk how the commercial edition handles that core. The docs say the commercial editions keep Nagios only as an optional core for migration, so treat it as a transition aid rather than the target. Rebuild the configuration on the Micro Core where possible and document every rule that needed a change. Your output is a list of migrated objects and a list of rules that were rewritten, each signed off by the monitoring owner.
Validate checks and notifications in parallel
Run the new site in parallel with Community and compare discovered services, check states and thresholds host by host. Trigger test notifications through every channel, including email, chat and paging integrations, and confirm that escalation rules fire as designed. Confirm with the vendor how long a parallel run should last for your environment, since no duration is set here. Your output is a reconciliation report showing matched services, known gaps and tested notification paths.
Cut over and retire the old notifications
Once the reconciliation report shows no unexplained gaps, switch the monitored hosts' agents and notification routing to the commercial site and disable the Community site's notifications so alerts do not duplicate. Keep the Community site intact, not deleted, until the commercial site has run through a full operating cycle. Your output is a dated cutover record and a confirmed single source of alerts.
Document the fallback to Community
If the subscription lapses, confirm with Checkmk what happens to your commercial site, which features stop working and whether you can return to a Community site. Keep backups of the configuration and a tested restore path for the Community site, and record which commercial-only features, such as push-mode agents and distributed monitoring, you would need to replace. Your output is a written fallback runbook reviewed by the people who would execute it.
Questions buyers ask before paying for Checkmk
What does Checkmk Community cost in licenses?
Checkmk Community carries no license fee. The Checkmk editions page describes it as free and open source monitoring for small infrastructures, easily scalable up to about 100 hosts, and the Checkmk source repository is licensed under GPL-2.0. Your costs are the server hardware or virtual machine, the operating system, your staff time to install, configure and patch it, and any outside help you choose to buy. Confirm with Checkmk GmbH that the free edition still fits your host count before you commit to it.
How much do Checkmk Pro and Ultimate cost per month?
The Checkmk editions page lists Pro from 190 euros per month and Ultimate from 275 euros per month, both billed annually. Those figures are list prices from that page at the time of research, so confirm the current figures and any volume terms with Checkmk before budgeting. Subscriptions are recurring, so the annual cost repeats for as long as you keep the edition. Ask whether your quote covers the number of hosts or services you plan to monitor and which support level applies.
How much effort does a move from Community to Pro or Ultimate take?
The effort depends on how much you have built on the free edition, not on the license itself. Checkmk docs say the commercial editions create new sites with the Checkmk Micro Core by default, and they keep the Nagios core only as an optional core for migration, so a site move is a planned change to the core. Plan for time to test checks, rules and notifications on the new core, to review any custom plugins, and to confirm dashboards and reporting still behave. Ask the vendor or your implementation partner to list those items in the written scope before work starts.
Which work drives the cost of a Checkmk migration?
Four factors shape the work: the number of sites and hosts, how many custom checks and rule sets you maintain, how many integrations feed notifications or tickets, and how distributed your monitoring is. Distributed monitoring is a Pro feature, so a team that moves from a single Community server to several remote sites will add design and testing time. Ask for an inventory of hosts, services, custom plugins and integrations in the quote so the estimate reflects your environment rather than a generic one.
Can our own engineers run Checkmk without outside help?
Many teams run Community themselves, because installation is available as Linux packages for Red Hat-based systems, SUSE Linux Enterprise Server, Debian and Ubuntu, or as Docker container images. Running it well still requires someone who owns upgrades, backups, rule maintenance and alert tuning. Commercial editions add distributed monitoring, multi-tenancy and automated mass rollouts, which need planned ownership. A useful test is whether two named people can handle an upgrade and a restore without help. If not, a retainer or a fixed-scope engagement may be the cheaper path.
What should a Checkmk quote include from our side?
A quote is only as accurate as the scope it is built from. Prepare a host and service count by site, the operating systems and virtualization platforms in use, the notification and ticketing targets, your data residency and access rules, and the number of users who need access. State whether you need push-mode agents and automatic host registration, which are Ultimate features, and whether you need Synthetic Monitoring, which is an add-on for Pro and Ultimate. Ask the vendor to separate license, support and services costs so you can compare like with like.
When is Synthetic Monitoring or the Cloud edition a better fit?
Synthetic Monitoring suits teams that need scripted checks of web applications or services from the outside, and it is available only with Pro and Ultimate. Choose it when you must measure user-facing availability, not only host health. The Cloud edition suits teams that want Checkmk operated as SaaS, at 240 euros per month billed yearly and capped at 50,000 services according to the editions page. Choose self-hosting when data location rules, service counts above that cap or your own operating standards make a hosted server a poor fit. Compare both options before you sign.
What the free edition is missing for enterprise needs
The paid decision usually turns on five gaps: vendor support, distributed monitoring, advanced reporting, multi-tenant access for internal customers and automated rollouts. Community covers a small estate well, but the editions page positions it for small infrastructures scalable to about 100 hosts, and the gaps below appear as the estate, the number of internal teams or the change rate grows. Before you buy, list which of the five your environment already needs today and which it will need within the next budget cycle, because the answer decides whether Pro or Ultimate is the right tier.
Vendor support and distributed monitoring are the gaps most teams feel first. Community is free open-source software built on the Nagios core, so support comes from the community and from your own staff. Pro adds distributed monitoring and 8x5 support, according to the editions page. Ask the vendor for the written support hours, response targets and escalation path for your region, and confirm whether those terms apply to your remote sites. Advanced reporting and multi-tenant access are the gaps that involve people outside the operations team. Ultimate adds multi-tenancy, and Pro adds advanced analytics and reporting. Map which internal customers need their own views and which reports must reach auditors or service owners.
Some gaps can be closed by your own engineering, and others cannot. You can build reports from exported data, script rollout steps with configuration management, and put a reverse proxy or access policy in front of a shared site, though each of these becomes code you maintain. Vendor support, the Ultimate push-mode agents and automatic host registration, and the multi-tenant model in the product are features you cannot reproduce by writing scripts. Treat the self-built options as a cost to price against the license, and record which gaps you chose to close yourself so that a later audit or staff change does not leave an undocumented workaround in production.
How DeployOpen scopes and supports Checkmk editions
DeployOpen plans, implements, customizes, integrates, hardens, documents and supports self-hosted open-source platforms inside your own infrastructure, and Checkmk is handled the same way across editions. Work starts from a written scope that states which edition, which hosts and which features are in play, so the edition decision is made on your requirements rather than on the price list alone.
How we scope
- Written scope names the edition, host count, sites and whether distributed monitoring is needed for Checkmk Pro or Ultimate.
- Scope lists which add-ons, such as Synthetic Monitoring, are in or out, and why each one is needed.
- Most engagements are fixed-scope, with deliverables and timelines agreed in writing before any work starts.
How we build
- Installation covers the package or container method you choose, on the Linux distributions your environment already runs.
- Configuration covers the monitoring core, discovery rules, notifications and any agent rollout your chosen edition supports.
- Integration work connects Checkmk to your ticketing, identity and existing monitoring data sources under the agreed scope.
How we hand over
- Handover documents the site layout, edition features in use, upgrade path and the licensing facts you need to keep on file.
- Runbooks cover backups, restores, core migration steps and how to add or remove hosts within your license tier.
- Your team receives written evidence of what was configured, tested and left out of scope for future reference.
How we support
- Ongoing support, upgrades and continuous testing are available as retainers after the initial handover.
- Retainer scope is agreed in writing, including which Checkmk patch releases are applied and how change requests are handled.
- Ask for a quote built from your written scope, since DeployOpen does not publish a price list.
