Best Free Open Source Monitoring Tools in 2025

This list can be a great resource for Open Source monitoring tools in 2025. For this, we have reviewed more than 10 open source tools with different functions and ranked them with a series of explanations so that you can discover the tools you need.

There is no criterion for the ranking. A short description of the tools, how you can use them, a source link if any, and user comments, along with our impressions of the tool, will hopefully be enough to create an accurate and useful guide for you.

A small note: All open-source uptime monitoring tools require at least a moderate level of IT knowledge and experience. You’ll also need to invest some time in setting them up.

If you’re looking for a free uptime monitoring tool that works with just a few clicks, check out our "21 Free Website Monitoring Tools for 2025" guide!

1

Uptime Kuma

Uptime Kuma is a well-known open-source tool for monitoring website uptime. It has a simple, user-friendly interface that makes it easy to keep track of your website’s status and get real-time alerts when something goes wrong.

Features:

1. Monitor website, API, and server status.
2. Supports monitoring with different protocols (HTTP(s), TCP, ICMP).
3. Real-time notifications (email, Slack, Discord, etc.).
4. Web-based user interface.

Positive Reviews:

• Uptime Kuma is incredibly easy to set up and use. The UI is clean, and it supports multiple notification methods like Telegram, Discord, and email. Perfect for small to medium-sized projects.

Negative Reviews:

• While it’s great for basic monitoring, it lacks advanced features like detailed analytics or integrations with other tools like Prometheus.

Installation:

• You can download Uptime Kuma from GitHub and run it on Docker or your local server.

2

Prometheus & Grafana

Prometheus is an open-source system monitoring tool that provides a time-series database and integrates with Grafana for visualized charts. You can use these two tools together to track performance metrics, such as website uptime.

Features:

1. Monitor websites, servers, and applications.
2. Flexible querying and alerting mechanisms.
3. Web-based visualization (with Grafana).

Positive Reviews:

• Prometheus is a powerhouse for metrics collection, and Grafana’s visualization capabilities are unmatched. Together, they form a robust monitoring stack for any infrastructure.

Negative Reviews:

• The learning curve is steep, especially for beginners. Setting up and maintaining Prometheus can be complex, and Grafana dashboards require time to configure properly.

Installation:

• You can install Prometheus and Grafana on Docker or a local server. Prometheus monitors your site at regular intervals, and you can visualize the data using Grafana.

3

Netdata

Netdata is an open-source monitoring tool that tracks system performance and provides web-based visualizations. It can also monitor website uptime and display real-time performance data.

Features:

1. System and website monitoring.
2. Real-time graphs.
3. Comprehensive monitoring capabilities and alerts.

Positive Reviews:

• Netdata provides real-time monitoring out of the box with zero configuration. The granularity of metrics is amazing, and it’s lightweight on resources.

Negative Reviews:

• The sheer amount of data can be overwhelming, and the default dashboards are not always user-friendly. Long-term storage requires additional setup.

Installation:

• You can install Netdata on Docker or directly on your server to monitor real-time website performance.

4

Healthchecks.io (Open Source)

Healthchecks.io is another open-source tool used for website uptime tracking and service monitoring. It is typically used for scenarios where your website or API needs to be actively checked at specific intervals.

Features:

1. HTTP, API, and Ping-based monitoring.
2. Notifications (email, SMS, etc.).
3. Integration via API.

Positive Reviews:

• Healthchecks.io is perfect for monitoring cron jobs and scheduled tasks. It’s simple, reliable, and the open-source version is easy to self-host.

Negative Reviews:

• It’s very niche and only useful for specific use cases like cron monitoring. It doesn’t offer broader infrastructure monitoring capabilities.

Installation:

• You can install Healthchecks.io on your server or Docker by following the official setup guide.

5

Checkmk

Checkmk is an open-source tool used for infrastructure monitoring and system performance tracking. It is easily scalable and has a broad ecosystem.

Features:

1. Hardware and software monitoring.
2. Web-based user interface.
3. Advanced reporting and notification features.

Positive Reviews:

• Checkmk is feature-rich and supports a wide range of devices and services. The auto-discovery feature saves a lot of time, and the Raw Edition is great for small teams.

Negative Reviews:

• The interface feels outdated, and the documentation can be hard to follow. The Enterprise Edition has more features, but it’s not open source.

Installation:

• You can install Checkmk on Linux servers using DEB and RPM packages available on their downloads page.

6

Elastic Stack (ELK Stack)

Elastic Stack is an open-source tool primarily used for log analysis and monitoring. ELK consists of Elasticsearch, Logstash, and Kibana.

Features:

1. Real-time search and analysis.
2. Log management.
3. Visualization tools (Kibana).

Positive Reviews:

• The ELK Stack is incredibly powerful for log aggregation and analysis. Kibana’s visualization tools are top-notch, and Elasticsearch scales well for large datasets.

Negative Reviews:

• Resource-intensive and complex to set up. Managing Elasticsearch clusters can be challenging, and the learning curve is steep for beginners.

Installation:

• You can install Elasticsearch by following the instructions in the official documentation, which provides detailed steps for various platforms.

7

Sensu

Sensu is an open-source monitoring platform designed for cloud-based system monitoring. It is particularly suitable for microservices.

Features:

1. Modular and extensible.
2. Automation and event management.
3. Ideal for scalable infrastructures.

Positive Reviews:

• Sensu is highly flexible and integrates well with other tools. The ability to write custom checks and handlers makes it suitable for complex environments.

Negative Reviews:

• The initial setup and configuration can be daunting. Documentation is improving but still lacks depth in some areas.

Installation:

• You can install Sensu by following the instructions in the Sensu Go repository.

8

Prometheus Alertmanager

Prometheus Alertmanager works alongside Prometheus to collect monitoring data and send alerts, allowing system administrators to respond instantly.

Features:

1. Alert management.
2. Integration with Prometheus.
3. Compatible with notification services.

Positive Reviews:

• Alertmanager integrates seamlessly with Prometheus and provides robust alerting capabilities. The grouping and silencing features are very useful.

Negative Reviews:

• Configuring alerts can be tricky, and the YAML-based configuration is error-prone. It’s not a standalone tool and requires Prometheus to function.

Installation:

• You can install Prometheus Alertmanager by downloading the precompiled binaries from the official Prometheus website or by using the available Docker images.

9

VictoriaMetrics

VictoriaMetrics is a high-performance open-source tool designed for storing and querying large-scale time-series data. It is commonly used alongside Prometheus.

Features:

1. High-performance data storage.
2. Integration with Prometheus.
3. Scalability.

Positive Reviews:

• VictoriaMetrics is fast, efficient, and easy to set up. It’s a great alternative to Prometheus for long-term metric storage and querying.

Negative Reviews:

• The ecosystem is not as mature as Prometheus, and some users miss certain integrations or community support.

Installation:

• You can install VictoriaMetrics by following the instructions in the official GitHub repository.

10

Cacti

Cacti is an open-source tool used for network and system monitoring. Similar to Zabbix, it collects data on network traffic and system health.

Features:

1. Graphing and data visualization.
2. SNMP-based network monitoring.
3. Web-based user interface.

Positive Reviews:

• Cacti is a solid choice for network graphing and monitoring. It’s been around for years and has a large community for support.

Negative Reviews:

• The interface feels outdated, and setting up custom graphs can be cumbersome. It lacks modern features compared to newer tools.

Installation:

• You can install Cacti by following the instructions in their official documentation.

11

LibreNMS

LibreNMS is an open-source network monitoring software. It is highly automated and can be used to monitor network devices.

Features:

1. Automatic network discovery.
2. Advanced reporting and alerting systems.
3. Web-based interface.

Positive Reviews:

• LibreNMS is excellent for network monitoring with auto-discovery and a wide range of supported devices. The community is active and helpful.

Negative Reviews:

• The UI, while functional, isn’t the most modern. Some users report performance issues when monitoring large networks.

Installation:

• You can install LibreNMS by following the detailed instructions provided in their official documentation.

12

Monit

Monit is an open-source tool used for monitoring your systems and services. It checks the health of services and takes action when needed.

Features:

1. Lightweight and fast monitoring.
2. Notifications about service status.
3. Automatic restart operations.

Positive Reviews:

• Monit is lightweight and easy to configure. It’s perfect for monitoring processes and services on a single server.

Negative Reviews:

• It’s not designed for distributed systems or large-scale monitoring. The lack of a centralized dashboard can be a limitation.

Installation:

• For detailed installation instructions, refer to the Monit Installation Guide.​