Infrastructure monitoring
Self-hosted alternatives to PRTG Network Monitor, priced
2 open-source tools that can replace PRTG Network Monitor, each shown with what it would actually cost to run for a fleet of 25 servers. PRTG Network Monitor on the Subscription tier costs $174 a month at that size.
Start here
PRTG is not a hosted service: you install it on your own Windows server. Its figure here is the licence alone, so the server and the time to run PRTG itself are left out, which makes PRTG look cheaper than it is.
| Tool | Server only | With your time | vs PRTG Network Monitor | Operational weight | Licence |
|---|---|---|---|---|---|
| Checkmk Community | $26.40 | $139 | +$809 | medium | GPL-2.0 |
| Zabbix | $101 | $213 | -$1,869 | medium | AGPL-3.0 |
The final column is the 36-month difference: positive means self-hosting is cheaper.
Which one to pick
Checkmk Community 2,372 stars
The free, open-source edition of Checkmk, with the Nagios core and round-robin metric files that do not grow once created. It installs as one package containing every component it needs. The figures are our estimate: Checkmk does not publish a requirements table we could cite.
At 25 servers it needs 2.6 GB of memory and 11.2 GB of disk, which fits the Starter 4 GB at VPSServer for $22.00 a month. Setting it up is roughly 6 hours of work, then 1.5 hours a month to keep it healthy. Licence note: Checkmk Community is GPL-2.0. Several features, including the faster monitoring core, are only in the paid editions.
Full PRTG Network Monitor versus Checkmk Community breakdown · Checkmk Community at every fleet size
Zabbix 6,394 stars
Zabbix server, a database and the web frontend. Memory is fitted to Zabbix's own hardware table, which asks for 8 GB at 1,000 monitored metrics and 16 GB at 10,000, assuming about 100 metrics per server; beyond 100 servers this runs above Zabbix's own figures. Disk uses Zabbix's database formula at 90 bytes per value, 100 items per server refreshed every minute, 31 days of history and a year of trends: about 0.5 GB per server.
At 25 servers it needs 9.3 GB of memory and 32.5 GB of disk, which fits the Starter 16 GB at VPSServer for $84.00 a month. Setting it up is roughly 6 hours of work, then 1.5 hours a month to keep it healthy. Licence note: Zabbix is AGPL-3.0. That only matters if you modify Zabbix itself and offer it to others over a network.
Full PRTG Network Monitor versus Zabbix breakdown · Zabbix at every fleet size
How the pricing was established
PRTG Network Monitor pricing was read from its own pricing page on 2026-09-21, quoted in euros and converted at 1.1592 dollars to the euro, the Frankfurter, European Central Bank reference rates rate for 2026-09-11. Server prices come from the providers listed on the hosting page. The sizing model and the cost of your time are set out in full on the methodology page.