Nagios Core vs OP5 Monitor comparison

Nagios and ITRS are both solutions in the Network Monitoring Software category. Nagios is ranked #13 with an average rating of 8.3, while ITRS is ranked #38 with an average rating of 9.0. Nagios holds a 2.6% mindshare in NMS, compared to ITRS’s 0.7% mindshare. Additionally, 80% of Nagios users are willing to recommend the solution, compared to 100% of ITRS users who would recommend it.

Nagios Core

Read 51 Nagios Core reviews

4,252 Views
3,699 Comparison Views

80% willing to recommend

OP5 Monitor

Read 7 OP5 Monitor reviews

1,260 Views
1,071 Comparison Views

100% willing to recommend

Nagios Core

OP5 Monitor

Comparison Buyer's Guide

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Executive SummaryUpdated on Oct 9, 2024

Nagios Core and OP5 Monitor are competing solutions in network monitoring. OP5 Monitor is favored for its comprehensive features and user-friendly setup, though Nagios Core has more favorable pricing.

Features: Nagios Core offers an extensive plugin architecture for customization, system integration capabilities, and flexibility for IT professionals. OP5 Monitor provides advanced scalability, sophisticated visualization tools, and an enhanced user-friendly setup, attracting large enterprises needing detailed analysis.

Room for Improvement: Nagios Core could improve by simplifying its setup process, enhancing user interface design, and providing more customer support options. OP5 Monitor could benefit from a more competitive pricing model, additional customization features, and improving its open-source accessibility for community-driven enhancements.

Ease of Deployment and Customer Service: Nagios Core features a manual setup process, which offers flexibility but can be time-consuming, even providing basic support through community resources only. OP5 Monitor offers a streamlined installation with comprehensive support options, reducing troubleshooting time and facilitating easier onboarding.

Pricing and ROI: Nagios Core is open-source, minimizing initial costs, though it may incur higher long-term management expenses due to customization needs. OP5 Monitor requires a higher initial investment but presents a solid ROI through its efficiency and full feature set, appealing to organizations seeking expansive monitoring with quick returns.

To learn more, read our detailed Nagios Core vs. OP5 Monitor Report (Updated: August 2025).

Buyer's Guide

Nagios Core vs. OP5 Monitor

August 2025

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Review summaries and opinions

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:

Categories and Ranking

Nagios Core

Ranking in Network Monitoring Software

13th

Ranking in IT Infrastructure Monitoring

10th

Average Rating

8.2

Reviews Sentiment

7.0

Number of Reviews

Ranking in other categories

No ranking in other categories

OP5 Monitor

Ranking in Network Monitoring Software

38th

Ranking in IT Infrastructure Monitoring

37th

Average Rating

8.6

Reviews Sentiment

4.4

Number of Reviews

Ranking in other categories

No ranking in other categories

Mindshare comparison

As of September 2025, in the Network Monitoring Software category, the mindshare of Nagios Core is 2.6%, down from 3.3% compared to the previous year. The mindshare of OP5 Monitor is 0.7%, down from 0.8% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Network Monitoring Software Market Share Distribution
Product	Market Share (%)
Nagios Core	2.6%
OP5 Monitor	0.7%
Other	96.7%

Network Monitoring Software

Featured Reviews

Nishith-Vyas

Tech Lead at STL Digital Limited

Valuable reporting and alert system with room for PDF export improvements

The NetEase reporting structure needs improvement, especially the availability report, which is weak. It should be generated automatically with minimal human intervention and should be exportable as a PDF. Besides that, an integrated PDF export feature for reports is necessary. Also, the alert mechanism and graphing mechanism need to be integrated properly into Nagios Core. Currently, integrating these requires advanced Linux knowledge. Integration of more visualization tools like Grafana and Prometheus for better graphing and visualization is also recommended.

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Sumanth Arshanapally

Senior Analyst at HCLSoftware

Monitoring ease and cost-saving benefits enhance operational efficiency

The monitoring in OP5 Monitor is very easy because we can directly use custom plugins. We can write custom scripts and use those scripts directly. It's very low cost, open, and the dashboards are easy to see. We can extract the reports easily, and this is very easy to compare. Real-time monitoring in OP5 Monitor provides data every one minute or every five minutes, enabling us to get live data from the last one minute or last five minutes. OP5 Monitor gave us proper server availability, so we can always check whether a server goes down or the server CPU and memory decreases. Before reaching a particular bottleneck situation, we identified and fixed the issue, which helped us from a cost-saving business perspective. It helped us avoid application downtime.

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Quotes from Members

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:

Pros

"The good thing about Nagios Core is it covers everything."

"I like that it's very simple to install, easy to manage and deploy, and easy to use for monitoring."

"Nagios Core integrates with tools like Splunk, Datadog, or Dynatrace. It is usually used as a feed to provide more technical information about devices or hosts to another system."

"The solution's most valuable feature is that it offers proper alerting capabilities."

"The most valuable feature depends on the project. It's great if you need to check to ensure a service is running 24/7. I can use the full solution for free, and it's flexible. If I need to add a dashboard, I can integrate it with Nagios. Cloud synchronization is wonderful."

"I would rate the overall solution ten points out of ten."

"The solution is quite efficient."

"Dashboard provides monitor of total assets."

More Nagios Core pros

"OP5 Monitor is a great choice due to its being built on an open-source monitoring tool and provides ample opportunity for customization based on specific support requirements. It is also user-friendly and easy to manage with a wide range of plugins available for use. In comparison to other enterprise tools, such as Micro Focus, OP5 Monitor stands out for its features and cost-effectiveness, making it the best tool in the market. Customization is one of the key strengths of the tool and provides a lot of capabilities. Additionally, it is easy to find support and plugins for the tool through online resources."

"The best feature is that it is very relatable, stable, and scalable. The logger is a part of the software, but it's not the most important point of it."

"With limited hardware or a virtual machine, you can address a huge network, hundreds of thousands of elements that need to be monitored. Other commercial software is not on that level."

"The API makes it pretty easy to integrate with any system."

"It monitors and continuously tests everything that is of importance to you and your users. It could be everything from monitoring disk space to CPU usage to memory. It could include determining if the response time in your e-commerce platform is quick enough, or whether you have too many bounces from some of the pages on your website. You want to monitor anything that could cost you money or time or resources. You can do that with this system. It's very flexible."

"We can also observe whatever we want, and there are no limitations."

Cons

"The mapping is a little hard."

"The interface could be improved."

"The initial setup process could be easier."

"The tool needs to improve the integrations."

"The dashboard should be improved."

"Cloud monitoring is an area for improvement because there aren't too many plugins available."

"I believe Nagios Core will need to provide an option for big data platforms in the future."

"Making it a little easier to configure and set up from the start would help. There are multiple layers that you have to wade through to be able to set it up, to do it the right way, and to get it to do what you want it to do."

More Nagios Core cons

"The solution is useful for tweaking. However, there have been some negative experiences, such as limited report capabilities. The only report available is in PDF format, making it difficult for teams managing multiple servers to extract data in Excel format. The speaker recommends that the team improve the report capabilities to better serve users."

"They need to improve the dashboard interface."

"We do not get performance reports properly."

"OP5 lacks some visualization, a feature that makes some other products nice. Op5 is built for purpose, which is fine, but if you compare it with some new products, the visualization is not so appealing, especially for management... If you don't need fancy visualizations, OP5 is fine."

"OP5 Monitor could include application monitoring in addition to infrastructure monitoring. If application business transactions were monitored, it would be helpful."

"The user interface is not what we are used to these days, and should be improved."

"IT environments today are in constant flux. This is driven by the newer cloud technologies such as Kubernetes and Docker, etc. The whole Nagios-based monitoring system that OP5 is created on top of, is based on a host-service model. There is a need for a strategy on what to do with more dynamic environments. There is some cool stuff going on in that direction."

Pricing and Cost Advice

"We are using the free version of Nagios Core."

"It's free."

"The Nagios Core (PNP4Nagios + Core) is free and can be setup by Netadmin within a few hours. The only additional cost is the cloud server."

"We have saved a lot of time, money, and effort in reducing disaster times, which is owed to Nagios quick alerting."

"We are using the open-source, unpaid version."

"The enterprise version has technical support. The version we are using is free."

"It's free."

"The product is cheaply priced."

More Nagios Core pricing and cost advice

"It was not expensive. And because it's less demanding in terms of hardware, you don't have to pay for another SQL or other database license, and you can have a huge installation on one machine..."

"OP5 has a very low price as a solution, compared to many other solutions out there."

"The cost of the license and support are separate. If you want platinum call support, it will cost more than a regular call. I did not opt for it, as it is an additional cost."

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Top Industries

By visitors reading reviews

Computer Software Company

14%

Manufacturing Company

Government

Comms Service Provider

Government

19%

Manufacturing Company

10%

Financial Services Firm

Computer Software Company

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	20
Midsize Enterprise	11
Large Enterprise	22

By reviewers
Company Size	Count
Small Business	2
Large Enterprise	5

Questions from the Community

What do you like most about Nagios Core?

What I like about Nagios Core is that it helps me ensure everything is running smoothly by checking the status of hosts and services.

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What is your experience regarding pricing and costs for Nagios Core?

Nagios Core is a free and open-source product. We don't charge for the product itself, but we charge for the man-hour costs related to installation, configuration, ongoing operation, and maintenance.

See all answers

What needs improvement with Nagios Core?

The dashboard should be improved. It's very simple. I don't have a very clear or specific suggestion. You can change the skin of the dashboard, however, it's good for me.

See all answers

What is your experience regarding pricing and costs for OP5 Monitor?

The price for OP5 Monitor is fine, but we don't know the exact price because it was managed by us; the customer themselves bought it and gave it to us to monitor.

See all answers

What needs improvement with OP5 Monitor?

OP5 Monitor could include application monitoring in addition to infrastructure monitoring. If application business transactions were monitored, it would be helpful. For application-related issues, ...

See all answers

What is your primary use case for OP5 Monitor?

Our previous use case for OP5 Monitor was server monitoring.

See all answers

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Compared 7% of the time

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Compared 3% of the time

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Compared 21% of the time

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Compared 8% of the time

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Compared 6% of the time

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Compared 6% of the time

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Product Reports

Buyer's Guide

Nagios Core

August 2025

Download Nagios Core product report

Buyer's Guide

OP5 Monitor

August 2025

Download OP5 Monitor product report

Overview

This is IT infrastructure monitoring's industry-standard, open-source core. Free without professional support services.

Nagios

OP5 Monitor - The Complete Monitoring Solution

OP5 Monitor is a flexible and highly scalable monitoring solution for all sizes of environments. Use just one product to monitor your IT environment regardless of location, whether on-premise, in dynamic environments, public cloud or a hybrid of these.

Digital transformation adds extra layers and complexity to the IT estate by creating a hybrid IT environment of both static and dynamic environments, that can be difficult to monitor efficiently. ITRS OP5 Monitor gives enterprises full visibility over their entire IT estate through a single pane of glass, allowing them to consolidate monitoring tools and cut down costs.

ITRS

Sample Customers

Airbnb, Cisco, PayPal, FanDuel

Svenska Spel, Carus, VGL, Tele2, Viking Line, Clas Ohlson, Vanderlande, Försäkringskassan

Buyer's Guide

Nagios Core vs. OP5 Monitor

August 2025

Free Report: Nagios Core vs. OP5 Monitor

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