Which fits your estate: PRTG or Checkmk
PRTG fits best when your estate is small or mid-size, already standardized on PRTG sensors, and your staff know the tool well enough that retraining would cost more than the license. Checkmk fits when your estate is Windows-heavy or mixed, when you want to keep monitoring data and the platform under your own control, and when you want agent-based discovery that registers hosts and their services automatically. If your renewal is the trigger, the question is less about which tool is better in general and more about which one your team can run for the next several years at the scale you expect.
Checkmk Community is free and open source, and its own editions page describes it as suited to small infrastructures and scalable to about 100 hosts. Beyond that, the decision moves to edition features. The push-mode agents and automatic host registration are listed as Ultimate features in the setup guide, so if your Windows fleet depends on them, confirm the edition before you plan the design. Pro adds distributed monitoring, automation and 8x5 support, which matters if you run remote sites or need a support window. Ask the vendor to confirm current edition pricing in euros on the Checkmk editions page against your host count, because pricing there is per edition, not per sensor.
The decision turns on four things: how many hosts and services you will monitor in two or three years, which agent behaviors your Windows and Linux servers need, which edition features you must have, and who will operate the platform after go-live. Put a named owner on the operations role, since an unowned monitoring server is the most common reason either tool loses value. If your sensor count is growing faster than your host count, model both sensor-based and service-based licensing with your real numbers before you sign anything.
Which option fits each scenario
This table maps common PRTG situations to the better fit between staying on PRTG, running free Checkmk Community, or moving to a Checkmk commercial edition. Read each row for the condition that changes the answer, since host count, agent features and staffing matter more than the product name.
| Scenario | Better fit | Condition that makes it so |
|---|---|---|
| Windows-only server estate with few network devices | Checkmk Community, if host count stays within about 100 | Community is free and open source, described as suitable for small infrastructures and scalable up to about 100 hosts on the Checkmk editions page. Confirm agent behavior for your Windows versions first. |
| Mixed Linux and Windows estate with hundreds of hosts | Checkmk Pro or Ultimate | Community is described as scaling to about 100 hosts, so larger estates need a commercial edition. Pro adds distributed monitoring, and the commercial editions default to the Micro Core. |
| Team that needs push-mode agents or automatic host registration | Checkmk Ultimate | Push-mode agents and automatic host registration are Ultimate features according to the Checkmk setup guide. Pro and Community do not include them, so confirm this for your target version. |
| Need for synthetic checks | Checkmk Pro or Ultimate | Synthetic Monitoring is an add-on available only with Pro and Ultimate per the Checkmk editions page. Community cannot run it, so budget the add-on as a separate line. |
| Network-heavy estate using PRTG mainly for switches and routers | Checkmk Community or a dedicated network tool | Checkmk covers SNMP devices, but if network discovery and traffic billing are the core need, compare with LibreNMS before committing. Confirm device coverage in a pilot. |
| Small team with no dedicated monitoring staff | Stay on a managed or hosted option, or Checkmk Community with a support partner | Community is free to license but someone must install, patch and tune it. If nobody on staff can own this, the setup and upkeep cost may exceed the PRTG subscription. |
| Environment with strict data residency or air-gapped requirements | Self-hosted Checkmk Community or a commercial edition | Checkmk installs on Red Hat-based systems, SUSE, Debian, Ubuntu or as Docker images, so monitoring data stays in your network. Appliances are available only for commercial editions. |
Where monitoring data lives and who controls it
Monitoring data holds host inventories, credentials used for polling, network topology and alert history, so where the server runs matters as much as what it measures. PRTG and Checkmk differ mainly in who hosts the monitoring core and who holds the keys to it. The cards below cover the decisions an audit or compliance team will raise first.
Choose the deployment model
PRTG runs on premises or as PRTG Hosted Monitor, so the vendor operates the hosted option. Self-hosted Checkmk runs on your own Linux servers, from the Red Hat, SUSE, Debian or Ubuntu packages, or as Docker container images. Checkmk Cloud is a SaaS option that moves the monitoring core to the vendor's environment. Decide which model fits your data residency rules before comparing features, because it changes who can reach the raw data.
Map where the data physically sits
Monitoring stores hostnames, IP addresses, service states, performance history and sometimes application or database identifiers. Ask whether PRTG Hosted Monitor data is held in a region you can name, and whether Checkmk Cloud would hold it outside your own network. For a self-hosted Checkmk site, the data stays in the servers and storage you control, including backups of the site directory. Write the location down for each data class.
Set retention you can prove
Retention is a setting you own only where you run the server. Confirm the history period and the storage used for metrics, event logs and notifications in each option, and whether an export can be taken before a subscription or service change. In a self-hosted Checkmk site, retention follows the storage and backup policy you set. Document the chosen periods so an auditor can compare them with your records retention schedule.
Control access to the monitoring server
A monitoring server holds credentials for Windows, SNMP and cloud accounts, so it is a high-value target. For PRTG on premises, review who holds administrator rights and which service account runs the probes. In Checkmk, define roles and contacts per site, restrict who can edit credentials and rules, and limit administrative shell access to named staff. Record who can read raw data versus change configuration.
Plan agent and network trust
Agents and remote probes send data from monitored hosts back to the server, so their transport and certificates define the trust boundary. Push-mode agents and automatic host registration are Checkmk Ultimate features, so a pull-mode design on Community or Pro leaves a different set of controls to document. Confirm how each agent authenticates, which ports cross network zones, and how certificates are issued and rotated.
Prepare evidence for the assessor
Auditors usually ask who can access monitoring data, where it is kept, how long it is kept, how changes are logged and how backups are restored. DeployOpen can prepare the configuration, access reviews and evidence for those questions, but it does not issue audit reports or certifications. Confirm the specific control requirements and evidence formats with your own assessor before the migration starts.
How PRTG and Checkmk compare on capabilities
This table compares how PRTG and Checkmk handle discovery, agents, SNMP, distributed monitoring, reporting, synthetic checks, the core engine, installation and appliances. Checkmk entries come from its editions and setup documentation, while PRTG entries point you to Paessler's current documentation for confirmation. The main takeaway is that several Checkmk capabilities depend on the edition you choose, so match the edition to the features you need before comparing costs.
| Capability | PRTG | Checkmk |
|---|---|---|
| Auto-discovery | Confirm discovery methods, scan schedules and sensor suggestions in Paessler's current documentation. | Automatic host registration is an Ultimate feature. Community and Pro require manual host setup. |
| Windows and Linux agents | Confirm which agent options ship with your PRTG version and how they are licensed. | Push-mode agents are an Ultimate feature. Confirm the agent types available in Community in the setup guide. |
| Network devices through SNMP | Confirm SNMP sensor coverage and how each device counts toward your sensor tier with Paessler. | Confirm SNMP support and device coverage for your edition in Checkmk's current documentation. |
| Distributed monitoring | Confirm how remote probes are deployed and licensed in Paessler's documentation. | Listed as a Pro and Ultimate feature. Community is not listed for it. |
| Reporting and analytics | Confirm which built-in report types and scheduling options your subscription includes. | Advanced analytics and reporting are a Pro and Ultimate feature. |
| Synthetic monitoring | Confirm whether web and transaction checks are included in your subscription. | Synthetic Monitoring is an add-on available only with Pro and Ultimate. |
| Core engine | Confirm the engine architecture and scaling limits with Paessler before sizing a deployment. | Community runs on the Nagios core. Commercial editions create new sites on the Checkmk Micro Core by default. |
| Installation options | On premises or as PRTG Hosted Monitor. Confirm supported operating systems for the server. | Linux packages for Red Hat-based systems, SUSE, Debian and Ubuntu, or Docker images for Community and commercial editions. |
| Virtual or physical appliance | Confirm appliance availability with Paessler before planning hardware. | Appliances are available only for commercial editions. Community is installed as software. |
How Checkmk discovers hosts and runs agents on Windows
Checkmk builds its service list through discovery, and most of that work happens after a host is added. Once a host exists in a Checkmk site, the service discovery function scans it and proposes the checks it can run, such as CPU, memory, disk, and Windows services. An administrator reviews those proposals and accepts them, so the monitored inventory reflects a decision rather than an unreviewed scan. On Windows and Linux alike, the data usually comes from the Checkmk agent installed on the host, which reports system information to the site. Teams comparing PRTG should map each sensor they rely on to a Checkmk service and confirm during a pilot that discovery finds the same items, especially for Windows services, event logs and disk counters.
The key distinction is between pull-style checks and push-mode agents. In a pull model, the Checkmk site contacts the host at each check interval, which is the model most teams know from PRTG sensors. In push mode, the agent on the host sends its data to the site on its own schedule, which can simplify firewall rules and suits hosts that are hard to reach from the monitoring server. Automatic host registration, which lets new hosts appear without manual entry, belongs to Checkmk Ultimate along with push-mode agents, according to the Checkmk setup guide and editions page. A Windows-heavy estate that depends on push agents or mass rollout should therefore price the Ultimate edition into its comparison, not the Community edition, before assuming the free option covers the design.
For agent installation steps, packaging and the exact options for each edition, use the Checkmk setup guide as the reference. Before committing, run a short pilot on a representative set of Windows servers, record how many hosts need manual registration, and check whether the firewall policy allows the pull model. Those results determine whether the cost of Ultimate is a fixed line item or an avoidable one, and they feed directly into the licensing comparison later on this page.
Which Checkmk edition you need and how licensing compares
Checkmk Community is the free, self-hosted edition, and it is the natural starting point for a team that wants to trial Checkmk without a purchase order. It is built on the Nagios core, and Checkmk's editions page positions it for small infrastructures that can scale up to about 100 hosts. It suits a bounded Windows and Linux estate run by a team with the time to maintain it.
- No license fee: Community carries no subscription. The recurring costs are the server, the operating system and the staff time for upgrades and day-to-day care.
- Host ceiling: The editions page describes Community as scalable up to about 100 hosts, so compare your host count against that figure, not your sensor count.
- Core engine: Community runs on the Nagios core. The commercial editions create new sites with the Checkmk Micro Core by default and keep Nagios only as an optional core for migration.
- Install options: Community installs from Linux packages for Red Hat-based systems, SUSE Linux Enterprise Server, Debian and Ubuntu, or from Docker images. Virtual and physical appliances are commercial only.
- Reviewable source: The Checkmk repository is GPL-2.0, so your engineers can read and build the code.
Check your host count and the number of hosts you expect to add over the next planning period before you accept Community as the long-term choice.
Pro is the first commercial edition and is aimed at teams whose single Community site has become hard to run, or whose operations group needs reporting and longer support hours. It adds advanced analytics and reporting, automation, distributed monitoring and 8x5 support. The editions page lists it from 190 euros per month, billed annually.
- Analytics and reporting: Pro adds advanced analytics and reporting. Map the reports your PRTG team uses today to the Checkmk views before you assume the gap is closed.
- Distributed monitoring: Use this when checks must run from remote sites or segmented networks and results must return to one central view.
- Support hours: 8x5 support is included. Confirm the hours and response terms against your incident process, especially for out-of-hours events.
- Synthetic Monitoring: This is an add-on available only with Pro and Ultimate, so budget for it separately if you need external checks.
- Recurring cost: The monthly rate is billed annually, on top of the server and the staff who run the site.
Ask Checkmk whether the Pro price changes with host or service count and what the 8x5 support covers before you compare the annual total with your current PRTG renewal.
Ultimate is the top self-hosted edition. It adds full-stack observability, multi-tenancy, advanced security compliance and automated mass rollouts. It fits a large or segmented estate where several groups need separate views, or where many new Windows hosts must be onboarded without manual steps. The editions page lists it from 275 euros per month, billed annually.
- Push-mode agents and automatic registration: The setup guide lists both as Ultimate features. They matter most on Windows-heavy fleets where machines appear, change and retire often.
- Multi-tenancy: Separate views for business units, subsidiaries or customers can be managed from one installation.
- Automated mass rollouts: Use them to deploy agents across many machines in one operation rather than host by host.
- Security compliance: The editions page lists advanced security compliance. Confirm which checks it covers and map them to your own control framework with Checkmk.
- Full-stack observability: This extends monitoring beyond infrastructure checks, so define the application and service scope before you buy.
Request a demonstration of push agents and mass rollouts in your own environment before you assume they will replace your current deployment method.
The Cloud edition is Checkmk's SaaS option. It is listed at 240 euros per month, billed yearly, and capped at 50,000 services. Checkmk runs the site, so the choice is about hosting, not only features. It fits teams that accept monitoring data hosted outside their own infrastructure. It does not fit a requirement that monitoring stay on the organization's own servers.
- Service cap: The cap is 50,000 services, which is a service count, not a host count. Convert your PRTG sensor inventory to services carefully before you rely on the cap.
- Data hosting: Checkmk hosts the site. Confirm the hosting location, data handling terms and how you export configuration and history.
- Operations load: Your team carries less server work, but it still owns host configuration, integrations and notification rules.
- Recurring cost: The yearly-billed rate is the main subscription cost. There is no server cost for the site, but integration and migration effort remain.
- Exit path: Confirm how you would move from Cloud to a self-hosted edition later, including what data and configuration can be exported.
Confirm the hosting location, the service cap and the exit path before you choose the Cloud edition over a self-hosted one.
PRTG and Checkmk price on different units. PRTG licenses by sensor, so the tier you need depends on how many sensors your devices create, and that number can rise quickly on Windows servers with many counters. Checkmk licenses by edition and, for Cloud, by services. Community has no license fee. Confirm the current PRTG tier and sensor counts with Paessler before any comparison, because tiers and counts change and no page can reflect your quote.
- Sensors versus services: A PRTG sensor and a Checkmk service are different units, so a one-to-one count will mislead you in either direction.
- Recurring fees: Checkmk Pro, Ultimate and Cloud are monthly rates billed annually. PRTG subscriptions also recur, so compare annual totals.
- Community boundary: The free edition has no license fee but stops at about 100 hosts, which can force a paid edition as the estate grows.
- Run cost: Servers, databases, staff time and migration effort are paid separately from either license.
- Quote items: Ask both vendors for the counting unit, the term, the renewal rule and the support hours included.
Build the comparison from your current host and sensor inventory, not from list prices alone.
What running Checkmk costs beyond the license
A Checkmk deployment has several cost lines, and only some of them are license fees. The cards below separate recurring subscriptions from one-time migration work and show what moves each line up or down, so you can ask vendors and integrators for comparable quotes.
PRTG subscription (recurring)
Your current PRTG spend is a recurring subscription sized by sensor tier, so the bill grows as you add sensors, devices and checks. Sensor count is the main driver, and a move to a higher tier or to Enterprise Monitor changes the line sharply. Before comparing, pull your current sensor count and renewal date from your PRTG license and record what you would stop paying for at the end of the subscription.
Checkmk Pro, Ultimate or Cloud fee
If you choose a commercial edition, the Checkmk editions page lists Pro from 190 euros per month and Ultimate from 275 euros per month, both billed annually, and the Cloud edition at 240 euros per month billed yearly, capped at 50,000 services. This fee recurs and is paid to Checkmk. Ask which edition covers push-mode agents and automatic host registration, since those are Ultimate features, and whether Synthetic Monitoring, a Pro and Ultimate add-on, is priced separately.
Community edition (no license fee)
Checkmk Community is free and open source, and the editions page describes it as easily scalable up to about 100 hosts. You still pay for servers, staff time and any support contract you buy elsewhere. Community is built on the Nagios core, while the commercial editions create new sites with the Checkmk Micro Core by default. Check whether your host count and feature needs stay within Community before you commit to it as the long-term plan.
Servers, storage and sites
Infrastructure cost is recurring and scales with host count, service count, check frequency and the number of distributed monitoring sites. Checkmk installs on Red Hat-based systems, SUSE Linux Enterprise Server, Debian, Ubuntu or as Docker images, and appliances are available only for commercial editions. Ask your team to size the monitoring server, the database and retention storage for your real service count, and to confirm whether remote sites need their own hardware in each location.
Operating staff time
Staff time is the largest recurring cost for many teams, and it is not on any vendor price list. It covers rule maintenance, discovery review, upgrades, backups and on-call response to alerts. Your in-house skills with Linux, Nagios-style configuration and the Checkmk rule model determine how many hours this takes. Ask any integrator to state the roles, hours per month and the skills they assume, so you can compare that figure with the time your current team spends on PRTG.
One-time migration and rule rebuilding
Moving from PRTG means exporting devices and sensors, creating hosts, reviewing service discovery, and recreating thresholds, notification rules and dashboards by hand. This work is one-time, but it can be the largest single cost in the first year, especially for Windows-heavy estates with many custom sensors. Ask for the scope of rule rebuilding, a parallel-run period in which both tools alert, and who signs off that alerts match before PRTG is switched off.
What a move from PRTG to Checkmk involves
The sequence turns PRTG's device and sensor inventory into Checkmk hosts and services, then retires PRTG only after alerts in both systems agree. The effort depends mostly on how many custom sensors and maps the PRTG installation contains.
Confirm the edition and inventory custom work
Decide between Checkmk Community and a commercial edition before any build starts, because the commercial editions add features such as distributed monitoring, push-mode agents and automatic host registration, and Checkmk's editions page lists the current tiers. In parallel, count the PRTG devices, sensors, custom sensors, maps, notification templates and scheduled reports, since these drive the effort more than the device count. Done when you have a written inventory and a named edition that the team has approved.
Export the device list through the PRTG API
Pull device, sensor and group data from the PRTG HTTP API in a format your team can parse, such as XML, JSON or CSV, and store the export under version control or in a restricted repository, since it contains internal addresses and naming. The PRTG administrator or a platform engineer usually runs this step, using an account with read access. Done when the export is complete, you can reproduce it, and each device maps to a host name and address that the team has reviewed.
Install Checkmk on Linux or as a container
Install the chosen Checkmk edition on a supported Linux distribution using the Linux packages, or run it as a Docker container image, following the Checkmk setup guide for your platform. Provision the server, storage and backups in your own infrastructure first, then create the monitoring site and confirm that the web interface and core start cleanly. Done when a test host can be added and checked successfully and the site passes its own health checks.
Create hosts and run service discovery
Import the reviewed device list into Checkmk as hosts, then run service discovery on each host so Checkmk proposes services for the checks it finds, such as CPU, disk, memory and interface status. Agents are needed for Windows and Linux hosts where you want deeper data, and this is where Windows-heavy estates need the most attention. Done when every host has a discovery result, unexpected services are reviewed, and the host count matches the inventory.
Recreate thresholds and notification rules
Rebuild the alert thresholds that PRTG sensors used, along with contacts, notification rules and escalation paths, using Checkmk's rule-based configuration rather than copying sensor settings one by one. Custom sensors usually need a custom check or a manual service definition, so plan those separately. Done when a set of test alerts reaches the same people through the same channels as before, and each custom sensor has either a working equivalent or a documented decision to drop it.
Run both systems in parallel
Keep PRTG and Checkmk monitoring the same estate for a period agreed by your team, and compare alert events, outage records and notification delivery between them. Investigate every difference, whether it is a missing alert, a false positive or a delayed notification. Done when the team signs off that Checkmk raises the same important alerts for the agreed test set, and the differences that remain are understood and accepted.
Retire PRTG sensors and archive history
Pause PRTG sensors in stages, starting with lower-risk groups, and remove notification paths only after the Checkmk equivalents are confirmed. Export historic data and reports from PRTG before the subscription ends, so you keep the records your auditors or service teams need. Done when PRTG no longer sends alerts, its archived exports are stored under your retention policy, and the runbook reflects Checkmk as the system of record.
Questions buyers ask before choosing Checkmk over PRTG
Can Checkmk Community cover our estate without a paid edition?
Checkmk Community can cover small infrastructures, and the editions page describes it as easily scalable up to about 100 hosts. Above that size, or when you need features outside Community, the Pro or Ultimate edition becomes the practical step. Count hosts the way Checkmk does, and check the current host and service limits with Checkmk before you size the platform, because your sensor count in PRTG does not map one to one onto hosts. Windows-heavy estates often need agents on each server, so confirm agent coverage for your operating systems during scoping.
Which Checkmk features require the Pro or Ultimate edition?
Several features that matter for PRTG replacement sit above Community. According to the editions page, Pro adds advanced analytics and reporting, automation, distributed monitoring and 8x5 support, and Synthetic Monitoring is an add-on available only with Pro and Ultimate. Push-mode agents and automatic host registration are Ultimate features, per the setup guide. Ultimate also adds multi-tenancy and automated mass rollouts. Map your current PRTG usage against this list before deciding, since a team that relies on push agents for Windows fleets will need Ultimate from the start.
How does Checkmk licensing compare with PRTG sensor licensing?
PRTG licenses by sensor count, so growth in monitored items raises the subscription tier. Checkmk commercial editions are priced per service on the editions page, with Pro listed from 190 euros per month and Ultimate from 275 euros per month, both billed annually. Community carries no license fee. Because the two models count different things, a one-to-one sensor comparison will mislead you. Ask your vendor or partner to convert your current sensor inventory into a service count, then compare the annual totals including support.
How long does a move from PRTG to Checkmk take?
The duration depends mainly on sensor count, the number of PRTG maps and dashboards, notification rules, and how many teams depend on the alerts. Each of these adds work because maps and notification templates generally have to be rebuilt by hand rather than exported. No duration is fixed here, so ask for a timeline in a written, scoped plan that lists the device groups, the sensor types to migrate and the alert paths to verify. Plan for an overlap period in which both systems run until alert behavior matches.
Can our own team migrate from PRTG to Checkmk?
Yes, a team with Linux administration and monitoring experience can install Checkmk from the supported Linux packages or Docker images and build the host list. The added work sits in tuning discovery rules, agent deployment at scale, notification design and the rebuilt dashboards. If you plan to use Ultimate features such as push-mode agents, budget for that learning curve as well. Teams with few spare engineers often find the cutover and parallel run the hardest part, so decide early who owns that window.
What does a Checkmk migration need from our side?
Expect to provide administrative access to the PRTG server and its API, a current inventory of devices and sensors with their thresholds, and access to the Windows and Linux hosts where agents will run. You also need a named owner who approves alert rules and escalation paths, because an alert that works in Checkmk but reaches the wrong person is still a failed migration. Ask for an inventory export and a list of custom sensors, since these need separate attention.
When should we bring in an implementation partner for this move?
A partner makes sense when staff time is scarce, when the monitoring estate is large or heavily customized, or when you need compliance evidence for the change, such as documented controls and test records. DeployOpen plans, implements, integrates and documents self-hosted platforms in your own infrastructure under a fixed scope agreed in writing, and it prepares evidence for compliance assessments but does not issue audit reports. Ask any provider for a written scope, deliverables and a quote that follows from it.
How DeployOpen helps you evaluate and move to Checkmk
DeployOpen is a Chainscore Labs company that plans, implements, hardens, documents and supports self-hosted open-source platforms inside your own infrastructure. For PRTG vs Checkmk, we start with a written scope that tests Checkmk against your Windows and mixed estate before any migration decision is made.
How we scope
- Inventory your PRTG devices, sensor types and Windows agent coverage to define what Checkmk must monitor.
- Compare sensor counts against the Community host limit and the Pro or Ultimate features your estate requires.
- Agree the written scope, deliverables and timeline before any work starts, since engagements are fixed-scope.
How we build
- Install Checkmk on Linux or Docker in your environment and configure sites, distributed monitoring and access controls.
- Set up service discovery, host groups and thresholds, then test alert routing against your existing notification rules.
- Run Checkmk and PRTG side by side so you can confirm that alerts and coverage match before cutover.
How we hand over
- Document the architecture, host and service configuration, notification rules and the edition decision with its reasons.
- Deliver runbooks for adding hosts, updating agents, upgrading Checkmk and restoring the site from backup.
- Walk your operations team through the handover so they can run monitoring without us.
How we support
- Ongoing support, upgrades and continuous checks are available as a retainer after handover.
- Review each Checkmk patch release against your configuration before applying it in your environment.
- Confirm current edition limits, prices and feature availability directly with Checkmk when you request your quote.
