Best Network Monitoring Software · 2026
Nagios XI vs 
PRTG Network Monitor Nagios XI vs PRTG Network Monitor: on our data-weighted scoring, Nagios XI edges ahead (8.0 vs 8.0/10). Nagios XI starts at $2595/one-time (100 nodes, Standard) and is best for teams wanting on-prem, perpetually-licensed infrastructure monitoring with a free open-source core; PRTG Network Monitor starts at Free tier available and is best for teams wanting sensor-based monitoring with a free tier. Choose Nagios XI for the stronger overall track record; consider PRTG Network Monitor if its pricing model or fit matches your environment better. Side-by-side table below.
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Six criteria, each scored 0–10 on the same scale from real review data, public pricing and feature coverage. See our methodology →
| Criterion | Nagios XI | PRTG Network Monitor |
|---|---|---|
| Editorial | 8.0 | 8.0 |
| User reviews | 9.0 | 9.2 |
| Adoption | 4.6 | 6.4 |
| Affordability | 9.5 | 9.5 |
| Feature breadth | 6.0 | 5.0 |
| Ease of trial | 10.0 | 10.0 |
| Nagios XI | PRTG Network Monitor | |
|---|---|---|
| Starting price | $2595/one-time (100 nodes, Standard) | Free tier available |
| Pricing model | per device | per sensor |
| Free trial / tier | Free tier + 30 days | Free tier + 30 days |
| Best for | Teams wanting on-prem, perpetually-licensed infrastructure monitoring with a free open-source core | Teams wanting sensor-based monitoring with a free tier |
| Deployment | On-prem | On-prem + cloud |
| G2 rating | 4.5/5 (55) | 4.6/5 (250) |
| Capterra rating | — | — |
| Our score | 8.0 | 8.0 |
You need teams wanting on-prem, perpetually-licensed infrastructure monitoring with a free open-source core.
You need teams wanting sensor-based monitoring with a free tier.
PRTG Network Monitor bills on a per sensor model from Free tier available (free tier available), while Nagios XI uses a per device model from $2595/one-time (100 nodes, Standard) (free tier available). Because the models differ, the cheaper option flips depending on your fleet size — model both at your seat/endpoint count.
PRTG Network Monitor ships 5 headline capabilities (Sensor-based monitoring, SNMP/flow/packet, Custom dashboards, Alerting) and deploys On-prem + cloud. Nagios XI ships 6 (SNMP + network device monitoring, Perpetual on-prem licensing, Event-driven remediation, Free open-source core (Nagios Core)), deploying On-prem.
PRTG Network Monitor holds 4.6/5 (~250 G2 reviews); Nagios XI holds 4.5/5 (~55 G2 reviews). On our data-weighted score, PRTG Network Monitor edges ahead (8.0 vs 8.0/10). Pick Nagios XI instead when teams wanting on-prem, perpetually-licensed infrastructure monitoring with a free open-source core. See PRTG Network Monitor alternatives or Nagios XI alternatives.