Here are several totally free and open source network monitoring tools for Windows—no paid license needed, no time limits:
- Nagios Core
Powerful open-source monitoring for servers and networks.
https://www.nagios.org - Zabbix
Enterprise-grade, open-source monitoring—Windows agent available.
https://www.zabbix.com - Sniffnet
Modern traffic monitor focused on ease-of-use; GUI app.
https://github.com/GyulyVGC/sniffnet - EasyNetMonitor
Simple tool for monitoring connectivity to internet hosts—tray app, logs drops.
https://nicekit.com/net-monitor/best-free-net-monitor.htm - DL Network Monitor
Free app from Microsoft Store to monitor ping and connection status.
https://apps.microsoft.com/detail/9nhw8hq6kvq4?hl=en-US - Speed Test Loggger
Tests and logs download speed on intervals, monitors downtime.
https://loggger.com - LibreNMS
Flexible and scalable open source network monitoring—can run on Windows via Docker.
https://www.librenms.org
All of these tools are free forever: no paid upgrades, subscriptions, or feature limitations. Each is suitable for logging drops and connectivity events on Windows.Here’s a refined list of totally free network monitoring tools for Windows—no licenses or time limits required. All official URLs are included:
- Nagios Core
Enterprise-grade open source monitoring of networks, servers, devices.
https://www.nagios.org - Zabbix
Powerful network monitoring; Windows agent supported; free and open source.
https://www.zabbix.com - Sniffnet
Free, open-source traffic monitoring tool with easy GUI and advanced features.
https://github.com/GyulyVGC/sniffnet - EasyNetMonitor
Tray utility—monitors computers and hosts, logs outages.
https://nicekit.com/net-monitor/best-free-net-monitor.htm - DL Network Monitor
Free app for monitoring internet connectivity and logging dropouts.
https://apps.microsoft.com/detail/9nhw8hq6kvq4?hl=en-US - Speed Test Loggger
Automates and logs download speed drops; detects outages and changes.
https://loggger.com - LibreNMS
Free, scalable network monitoring for larger setups—Windows via Docker.
https://www.librenms.org
All above solutions are permanent free options, with no hidden upgrade costs.Here are totally free network monitoring tools for Windows systems—100% free, open source or freeware, no limited trial, no balloons:
- Nagios Core
https://www.nagios.org
Free, highly customizable open-source monitoring for devices, servers, and networks. - Zabbix
https://www.zabbix.com
Free, open-source enterprise-grade monitoring tool; supports Windows agents. - Sniffnet
https://github.com/GyulyVGC/sniffnet
Easy-to-use, open-source GUI traffic monitor—great for users who want simplicity. - EasyNetMonitor
https://nicekit.com/net-monitor/best-free-net-monitor.htm
Small Windows tray utility that monitors hosts and logs connection drops. - Speed Test Loggger
https://loggger.com
Free app to schedule, log, and monitor download speed and connection outages on Windows. - DL Network Monitor
https://apps.microsoft.com/detail/9nhw8hq6kvq4?hl=en-US
Microsoft Store app for basic ping and connectivity monitoring, totally free. - LibreNMS
https://www.librenms.org
Advanced, scalable open-source monitoring (Windows via Docker or VM).
These are all fully free with no subscription, license requirements, or limitations—just download and use.
Here’s a list of completely free, open-source network monitoring tools for Linux (desktop, server, or VM)—no paid license, no trial limits, all with their official URLs:
- Nagios Core
The classic open-source monitoring platform for servers, devices, and networks.
https://www.nagios.org - Zabbix
Feature-rich, scalable, and open-source network/SNMP monitoring.
https://www.zabbix.com - LibreNMS
Powerful, community-driven open-source monitoring with auto-discovery, maps, alerting, and API access.
https://www.librenms.org - Prometheus
Leading open-source observability tool; great for time-series data, dashboard, and alerting—often paired with Grafana.
https://prometheus.io - Sniffnet
Easy-to-use, open-source network traffic monitor for Linux desktops and servers.
https://github.com/GyulyVGC/sniffnet - Netdata
Real-time, highly visual system and network metrics for Linux servers.
https://www.netdata.cloud - ntopng Community Edition
Lightweight, real-time network traffic analyzer—great for LAN and server monitoring.
https://www.ntop.org/products/traffic-analysis/ntop/ - Icinga 2
Modern fork of Nagios with improved web interface, alerting, and scalability.
https://icinga.com
Every tool listed above is 100% free forever and supports Linux environments (including server-grade distros, VMs, and Docker containers). Whether you want basic traffic logs or deep SNMP and multi-server metrics, you have top-tier open-source options.Here is a list of totally free, open-source network monitoring tools for Linux (usable on servers, desktops, VMs):
- Nagios Core
https://www.nagios.org
Classic open-source network and system monitoring platform. - Zabbix
https://www.zabbix.com
Enterprise-scale monitoring for network, SNMP, and servers. - Netdata
https://www.netdata.cloud
Real-time system and network health monitor with beautiful dashboards. - LibreNMS
https://www.librenms.org
Powerful, extensible network monitoring (auto-discover devices, alerting, graphs). - Prometheus
https://prometheus.io
Highly scalable time-series data monitoring, often paired with Grafana for dashboards. - Sniffnet
https://github.com/GyulyVGC/sniffnet
Easy desktop traffic monitor, runs on Linux and Windows. - ntopng Community Edition
https://www.ntop.org/products/traffic-analysis/ntop/
Lightweight, real-time traffic analyzer; ideal for LAN, switch, and server monitoring. - Icinga 2
https://icinga.com
Modernized fork of Nagios with advanced web UI, alerting, and distributed monitoring.
All of these are free, open source, well-documented, and actively maintained, suitable for both home and enterprise scale Linux environments.Here’s a list of totally free, open source network monitoring tools for Linux, each with their official site:
- Nagios Core
https://www.nagios.org - Zabbix
https://www.zabbix.com - Netdata
https://www.netdata.cloud - LibreNMS
https://www.librenms.org - Prometheus
https://prometheus.io - Sniffnet
https://github.com/GyulyVGC/sniffnet - ntopng Community Edition
https://www.ntop.org/products/traffic-analysis/ntop/ - Icinga 2
https://icinga.com
All of these tools are fully free/open source, work on Linux (servers and desktops), and are well-supported for both home and enterprise-grade setups.Here are the best totally free, open-source network monitoring tools for Linux (no paid upgrades, no limitations):
- Nagios Core
https://www.nagios.org
Classic, enterprise-grade open-source monitoring. - Zabbix
https://www.zabbix.com
Advanced, scalable network and system monitor with Linux support. - Netdata
https://www.netdata.cloud
Real-time metrics and network traffic visualizer for Linux. - LibreNMS
https://www.librenms.org
Flexible and scalable network monitoring platform. - Prometheus
https://prometheus.io
Time-series metrics and alerting tool (best with Grafana dashboards). - Sniffnet
https://github.com/GyulyVGC/sniffnet
Easy GUI-based traffic monitor for Linux and Windows. - ntopng Community Edition
https://www.ntop.org/products/traffic-analysis/ntop/
Lightweight real-time network traffic analyzer. - Icinga 2
https://icinga.com
Modern monitoring, forked from Nagios—improved interface and scalability.
These are fully free forever and work on any standard Linux distro—suitable for home, lab, server, or VM setups.