no licence cost
Free & open-source network admin tools
13 tools you can download and run without paying for a licence —10 open-source and 3 freeware — across network scanning and monitoring. Each links to the vendor or project’s official download; nothing is hosted here.
network scanners
Network Scanners — 8 free
| Tool | Vendor | Type | Best for | |
|---|---|---|---|---|
| Nmap | Nmap Project | Open source · NPSL | Open-source network discovery and security auditing tool with a powerful scripting engine. | Details → |
| Wireshark | Wireshark Foundation | Open source · GPLv2 | Open-source packet analyzer for network troubleshooting, analysis and protocol inspection. | Details → |
| Angry IP Scanner | Anton Keks | Open source · GPLv2 | Lightweight, cross-platform open-source IP address and port scanner. | Details → |
| Advanced IP Scanner | Famatech | Freeware | Free Windows LAN scanner for device discovery, shared folders and remote access. | Details → |
| Fing | Fing | Freeware | Device discovery and network monitoring app for mobile and desktop. | Details → |
| Advanced Port Scanner | Famatech | Freeware | Free Windows port scanner for finding open ports and identifying services on a network. | Details → |
| Masscan | Robert Graham | Open source · AGPLv3 | High-speed open-source port scanner capable of scanning large IP ranges asynchronously. | Details → |
| Netdiscover | Netdiscover Project | Open source · GPLv3 | Open-source ARP reconnaissance tool for discovering hosts on local network segments. | Details → |
monitoring
Monitoring — 5 free
| Tool | Vendor | Type | Best for | |
|---|---|---|---|---|
| Zabbix | Zabbix | Open source · GPLv2 | Open-source enterprise monitoring for networks, servers, cloud and applications. | Details → |
| Nagios Core | Nagios Enterprises | Open source · GPLv2 | Long-standing open-source monitoring engine for hosts, services and network devices. | Details → |
| LibreNMS | LibreNMS Community | Open source · GPLv3 | Open-source auto-discovering network monitoring system with SNMP support and alerting. | Details → |
| Icinga | Icinga GmbH | Open source · GPLv2 | Open-source monitoring platform for hosts, services and network infrastructure, forked from Nagios. | Details → |
| Checkmk | Checkmk GmbH | Open source · GPLv2 | Infrastructure and network monitoring with an open-source Raw Edition and commercial editions. | Details → |
rmm
Looking for free RMM?
RMM platforms are mostly commercial, so none qualify as free or open-source here. A few do offer a free tier or trial for small fleets — see the RMM category for those options.
FAQ
Common questions
Are these tools completely free?
Every tool listed here is free to use for ongoing work — either open-source (free and modifiable, with source code available) or freeware (free of charge but proprietary). Commercial products that only offer a time-limited trial are not included on this page.
What is the difference between open-source and freeware?
Open-source software is released under a licence that makes the source code available and lets you inspect, modify and redistribute it (subject to the licence terms). Freeware is free of charge but proprietary — you can use it at no cost, but the source code is closed. Both are free to download and run.
Is there free RMM software?
Fully free, unlimited RMM is rare. Most RMM platforms are commercial, though several offer a free tier or extended trial for a small number of endpoints — see the RMM category for details on those options.