After 60 days, the trial reverts to the unless you purchase a standard license.

Getting Nagios XI running is surprisingly fast if you use their pre-built virtual machines.

The short answer is: However, there is an official free tier that is very generous for small environments, and there is always the original Nagios Core for those who want 100% free and open-source software.

The free license does not include direct technical support from Nagios; instead, users rely on the active Nagios Community Support . How to Get Nagios XI for Free

| If you want... | Then use... | | :--- | :--- | | To learn Nagios XI for work | Free License (7 nodes) | | To monitor your home lab (under 7 devices) | Free License (7 nodes) | | To monitor 50+ servers for free | Nagios Core | | An easy web GUI without paying | Free License (7 nodes) | | To test enterprise features before buying | 60-day trial |

If you need to monitor more than 7 devices with a GUI and can't pay, – just be ready to edit some configuration files by hand.