OpenNMS
OpenNMS: A broad, self-hosted monitoring platform for teams that want open-source control. Ranked #16 of 54 in Network Monitoring by our editors (7.7/10); pricing: Free plan; best for open-source distributed network monitoring.
At a glance
- Editor score7.7 / 10
- PricingFree plan
- Best forOpen-source distributed network monitoring
- Free planYes
- Synthetic checksYes
- Facts checked23 Sep 2026
Where it wins
- Free Horizon distribution with broad monitoring coverage
- Distributed monitoring through Minion
- Strong flow, topology, API, and notification integrations
Where it doesn't
- Self-hosted deployment requires infrastructure management
- The wide feature set may exceed small-team needs
- Paid Meridian tiers add planning around cores, devices, and Minions
Our verdict on OpenNMS
OpenNMS is an open-source network monitoring platform for telecom operators and enterprise IT teams. It covers faults, performance, traffic flows, applications, services, and topology across local and distributed environments. The platform is available as Horizon, a free community distribution, and Meridian, a subscription-based enterprise distribution. Its web interface, Linux support, and REST API suit organizations that want control over deployment and configuration.
Coverage is a major strength. OpenNMS combines alarm generation, threshold-based performance monitoring, service polling, application protocol testing, and discovery for networks, applications, services, and topology. Traffic analysis supports NetFlow, IPFIX, sFlow, and JFlow, while geographical, logical, and layered maps add visibility into network structure. Dashboards, resource graphs, reports, and charts support ongoing analysis. Minion extends monitoring to distributed environments, making the platform a stronger fit for multi-site infrastructure than a narrowly focused availability checker.
The surrounding ecosystem is broad, with integrations for Grafana, Jira, Slack, Mattermost, Kafka, ActiveMQ, Elasticsearch, LDAP/AD, and REST APIs. Notifications can use email, SMS, HTTP/webhooks, and other integrations. Meridian plans range from Basic and Standard to Essential, Premier, and Premier+, with increasing access to Meridian repositories, cores, Minions, Sentinel, and container images. Choose OpenNMS when open-source control, distributed monitoring, traffic visibility, and extensibility matter. A hosted service or a simpler monitoring tool may suit teams that want less infrastructure responsibility or a narrower operational scope.
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OpenNMS pricing
All 5 OpenNMS plans and prices →
OpenNMS fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Not verified |
| Synthetic checks | Yes |
| Device limit | Not verified |
| Traffic monitoring | Yes |
| Topology maps | Yes |
| Alert channels | Not verified |
| Deployment | Self_hosted |
| Deployment | Self-hosted |
| Platforms | Web, Linux |
| Support | Community, Docs · 24/7 |
| Built for | Small business, Mid-market, Enterprise (editorial estimate) |
| Pricing | Free plan (source) |
| Website | opennms.com |
| Facts checked | 23 Sep 2026 |
Alternatives to OpenNMS
- ZabbixBroad infrastructure monitoring with a free self-hosted edition and paid cloud options.9.4
- CheckmkA broad hybrid monitoring platform with a capable free edition and costly paid entry.9.3
- ManageEngine OpManagerBroad monitoring, mapping, traffic analysis, automation, and distributed coverage across four editions.9.1
See all OpenNMS alternatives →
Also Ranked In
OpenNMS is ranked in 8 of our directories; the 6 strongest besides Network Monitoring.
- #12Network Monitoring - Enterprise Software26 tools ranked
- #13Network Performance Monitoring Software26 tools ranked
- #17Network Monitoring - Midmarket Software29 tools ranked
- #25Alert Management Software36 tools ranked
- #29Network Topology Mapping Software45 tools ranked
- #34DNS Monitoring Software37 tools ranked
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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