PRTG vs Checkmk

For most IT teams choosing between these two tools in 2026, the decision is simpler than it looks. If your team runs Windows and you have industrial or IoT devices that speak Modbus, OPC UA, or MQTT. PRTG is the right call. No other tool in this category handles OT protocols as natively, and the GUI-driven experience on Windows is genuinely polished.

For everyone else (especially organizations with more than 100 hosts, Linux-competent admins, and a real interest in keeping licensing costs low), Checkmk Raw Edition is the answer. The auto-discovery depth alone saves dozens of hours in initial setup. The €0 licensing cost at any scale is a genuine structural advantage that compounds over years.

Checkmk is also the better choice for MSPs, cloud-native environments, and Kubernetes-heavy infrastructure. The 2,000+ check plugins and the mature distributed monitoring architecture give it genuine breadth that goes beyond what PRTG's sensor model can efficiently cover.

Short version: PRTG is the better tool for Windows-native, IoT/OT, and NetFlow-dependent environments where you can justify the sensor licensing cost. Checkmk is the better tool for scale, cost efficiency, Linux environments, and cloud monitoring, and for most teams at 100+ hosts, the cost argument alone makes Checkmk the default recommendation.

PRTG Network Monitor is built by Paessler AG in Nuremberg, Germany and has been a fixture in Windows-centric IT shops since 2003. It runs natively on Windows Server and models every metric as a sensor: a ping check, an SNMP OID, a NetFlow stream, a WMI counter. That model gives PRTG precise, per-metric billing and enormous flexibility, but it also means license costs grow faster than host counts.

Checkmk was created by Mathias Kettner in Munich, evolved out of the Nagios ecosystem, and is now developed commercially by Checkmk GmbH. Its Raw Edition is fully open-source and free forever with no artificial limits. Where PRTG requires you to manually configure each sensor, Checkmk auto-discovers 80 to 150 check items per host the moment you run its agent. Servers, switches, and cloud resources come fully monitored within minutes.

The core tradeoff: PRTG is a better-polished Windows-native tool with strong IoT and industrial protocol support, but its sensor licensing penalizes scale. Checkmk is a Linux-based, automation-first monitoring platform where the free tier genuinely covers most infrastructure teams, but it demands more Linux comfort and offers limited IoT protocol coverage.

PRTG pricing is straightforward in structure but catches buyers off guard in practice. A sensor is any single monitored metric: one ping check, one SNMP interface, one WMI CPU counter, one NetFlow source. A typical server consumes 10 to 20 sensors (CPU, memory, each disk partition, each network interface, services, event log). A managed switch with 24 interfaces and basic SNMP checks uses 30+ sensors easily.

Run that math on a real environment: 200 devices averaging 5 sensors each = 1,000 sensors, putting you at the €3,899/year tier. At 500 devices with the same average, you need 2,500 sensors at €7,899/year. The free tier covers only 100 sensors, enough for a home lab or a small branch office, not a production network. The full sensor tiers are: 500 sensors €1,799/yr, 1,000 sensors €3,899/yr, 2,500 sensors €7,899/yr, 5,000 sensors €12,899/yr, XL1 unlimited €15,899/yr. PRTG Hosted Monitor (SaaS) is priced separately and comparably.

Checkmk Raw Edition costs €0 and has no per-host limits. It is open-source (GPL), actively maintained by Checkmk GmbH, and includes the same monitoring engine as the paid editions. For a team comfortable running a Linux VM, the total infrastructure cost to monitor 500 hosts is the compute cost of that VM, typically under €50/month on any cloud provider. The Cloud Edition and Enterprise Edition require a custom quote; Checkmk does not publish per-host SaaS pricing publicly.

The cost gap is significant at scale. A 1,000-host environment in PRTG (at 5 sensors per host) requires the 5,000-sensor tier at €12,899/year. The same environment in Checkmk Raw costs €0 in licensing. Even factoring in the time to maintain a Linux VM, Checkmk is dramatically cheaper for large infrastructure. PRTG makes financial sense when IoT/industrial protocols, Windows-only teams, or the polished SaaS option justify the premium.

Choose PRTG when your environment includes industrial or IoT devices that speak Modbus RTU/TCP, OPC UA, or MQTT. No other mainstream monitoring tool in this price range handles OT protocols natively. If you're monitoring energy meters, PLCs, building management systems, or SCADA components alongside IT infrastructure, PRTG handles all of it from a single console.

Choose PRTG when your team administers Windows exclusively and has no Linux expertise. PRTG installs on Windows Server in under an hour. Its GUI-driven sensor configuration requires no scripting knowledge for standard checks. If hiring or training Linux admins isn't realistic, PRTG removes that dependency entirely, including for distributed monitoring, where remote probes also run on Windows.

Choose PRTG when NetFlow and sFlow traffic analysis is a daily operational need. PRTG's built-in flow analysis (identifying top talkers, tracking per-application bandwidth, and correlating traffic with alerts) is a genuine differentiator. Checkmk has no equivalent native capability and requires a separate flow tool like ntopng.

Choose PRTG when you want a polished SaaS option without managing infrastructure. PRTG Hosted Monitor gives you a fully managed cloud instance with the same sensor model. For organizations that need monitoring but can't run servers, it's a practical option. Checkmk's Cloud Edition is comparable but requires a custom quote and has less community documentation.

Choose Checkmk when licensing cost is a real constraint. The Raw Edition monitors unlimited hosts with all core features at no cost. For a budget-conscious IT team, a Linux-savvy admin, or any organization with 200+ hosts to monitor, the savings versus PRTG's sensor tiers are substantial, often €4,000, €13,000 per year at typical environment sizes.

Choose Checkmk when you want monitoring to deploy itself. The auto-discovery workflow is genuinely time-saving: install the Checkmk agent on a host, run discovery, and 80 to 150 checks are automatically configured and active within minutes. In a 500-host environment, that difference in initial setup time is measured in days, not hours.

Choose Checkmk when your infrastructure is Linux-heavy or cloud-native. The agent covers 100+ Linux check items per host out of the box. Cloud checks for AWS, Azure, and GCP are mature. Kubernetes monitoring (cluster, node, pod, container) is a supported first-class use case. PRTG's coverage in these areas exists but is noticeably thinner.

Choose Checkmk when you're running a managed services practice. The Enterprise Edition's multi-tenancy model (isolated sites per customer, centralized management) is purpose-built for MSPs. PRTG can be stretched into multi-tenant architectures but it isn't the primary design intent.

If your primary need is cloud infrastructure observability with metrics, logs, and traces in a single platform, both PRTG and Checkmk are largely network and server monitoring tools. Neither replaces a full observability stack. Datadog, Grafana Cloud, or New Relic are better starting points for APM-centric or microservices-heavy environments.

If you're a small MSP managing 10 to 30 clients with a mix of Windows and network devices and want an all-in-one RMM rather than a standalone monitoring tool, consider Auvik or NinjaRMM. They combine network monitoring with endpoint management and have onboarding workflows designed for MSP technicians rather than internal IT.

If your environment is dominated by Cisco or Juniper network infrastructure and you need advanced network performance management (capacity planning, config management, automated fault isolation), SolarWinds NPM or Cisco DNA Center are more appropriate than either PRTG or Checkmk.

Both PRTG and Checkmk cover the fundamentals: email, SMS, and webhook-based alerting that can push to Slack, Microsoft Teams, PagerDuty, and OpsGenie. At that level, the integration surface is comparable.

PRTG has a native IFTTT connector, a REST API for reading sensor data and triggering actions, and direct integrations with ServiceNow and Jira for ticket creation. The ecosystem is well-documented and has been built out over 20 years of customer requests.

Checkmk integrates with Grafana for dashboard visualization (a common pairing in Linux-heavy shops), and its notification engine can call any REST endpoint. The Checkmk Exchange hosts community-maintained integrations for tools like Ansible, Puppet, and SaltStack for automated remediation workflows.

For ITSM integration, PRTG has more polished out-of-box connectors. For infrastructure-as-code workflows, triggering monitoring configuration changes from Ansible playbooks or Terraform, Checkmk's API and community tooling is more developed.

Installing PRTG takes 30 to 60 minutes on a Windows Server. The setup wizard walks through initial auto-discovery, sensor templates, and notification configuration. Most teams have basic monitoring running the same day. The challenge isn't initial install. It's sensor sprawl: as you add devices and metrics, managing thousands of sensors requires discipline in naming, grouping, and applying templates.

Installing Checkmk Raw on a Debian or Ubuntu VM takes about the same time if you're comfortable with Linux package management. The agent rollout is the bigger investment: pushing the Checkmk agent to all monitored hosts (via GPO for Windows, package manager for Linux) and then running auto-discovery. In a 200-host environment, agent rollout with proper automation takes 2 to 4 hours. Without automation, it can stretch to a day.

Migrating from PRTG to Checkmk is technically a full replacement, not an upgrade path. There's no import tool that maps PRTG sensors to Checkmk checks. The migration approach is: run both in parallel, use Checkmk's auto-discovery to rebuild monitoring coverage, verify parity over 2 to 4 weeks, then decommission PRTG. Most teams discover that Checkmk auto-covers 90%+ of what they had manually configured in PRTG.

Migrating from Checkmk to PRTG follows the same parallel-run approach. The main migration task is counting your sensor needs before committing to a PRTG license tier: teams moving from Checkmk often undercount sensors, sign up for the 500-sensor tier, and find themselves needing to upgrade within 90 days. Audit your host count, estimate 5 to 15 sensors per device depending on type, and purchase accordingly.