NetAlertX vs WatchYourLAN in 2026: two self-hosted network monitors compared
Both tools answer the same worry: something joined my network and I want to know about it. They answer it at very different weights, and both stop short of the same question. Here is what each one actually does, based on their documentation as of August 2026.
Full disclosure: we build DeviceShelf Server, a commercial tool in the same space, and it appears at the end of this page. NetAlertX and WatchYourLAN are both good free software; for plenty of setups one of them is all you need, and we say below which setups those are.
The short version
Pick WatchYourLAN if you want the smallest possible tool that keeps an online/offline history and pings you about new hosts. Pick NetAlertX if you want presence monitoring as a project: more discovery sources, more integrations, more to configure. Pick DeviceShelf Server if the list itself is not enough and you also want to know what each device is, which ports it exposes, and how your infrastructure is doing, without assembling plugins.
NetAlertX
NetAlertX (formerly Pi.Alert) is the feature-rich option among the free presence monitors, written in Python and licensed GPL-3.0. It discovers devices through more sources than anything comparable: arp-scan sweeps, Pi-hole database and DHCP-lease imports, generic DHCP leases, a UniFi controller import, SNMP-enabled routers, plus a plugin system for more. On top of that sit presence tracking with alerts on connect, disconnect and IP change, workflow automations (auto-categorise, group by vendor, archive), a network topology view, multi-site sync, Prometheus metrics and notifications through Apprise with its 80+ services, alongside NTFY, Pushover and friends.
Install is Docker-first, with bare-metal Linux, a Home Assistant add-on and an Unraid app as alternatives. The project is actively maintained and popular, with about 6,900 GitHub stars. The trade-off is that the breadth wants attention: many sources, many settings, and a UI with a learning curve. What it deliberately does not do: deep device identification beyond the MAC vendor, port scanning, or a security report.
Best for: homelabbers who enjoy wiring discovery sources together and want maximum integration surface for free.
Where it stops: it tells you a device appeared, and its vendor. What the device is, and what it exposes, stays your homework.
WatchYourLAN
WatchYourLAN is the opposite philosophy: one lightweight Go binary around arp-scan, MIT-licensed. It keeps a list of every host it has seen, records online/offline history, and notifies about new hosts through Shoutrrr (Discord, e-mail, Gotify, Matrix, Ntfy, Pushover, Slack, Telegram, webhooks). It can export to InfluxDB2 or Prometheus for a Grafana dashboard, stores in SQLite or PostgreSQL, and ships as Docker image (host networking required), native packages (.deb, .rpm, .apk) and plain binaries.
The limits are the point. ARP scanning only, so no port information and no identification beyond the vendor prefix; history retention defaults to 48 hours (configurable); and there is no built-in authentication, so exposing the UI safely means putting a proxy or SSO like Authelia in front. For a tool you set up in ten minutes on a Pi, those are fair trades.
Best for: the minimalist answer to "tell me when something new joins", with Grafana as the optional pretty face.
Where it stops: everything beyond the ARP layer, and any question that starts with "what is this device".
Side by side
| Capability | NetAlertX | WatchYourLAN | DeviceShelf Server |
|---|---|---|---|
| Licence / model | Free, GPL-3.0 | Free, MIT | Commercial, part of the one-time licence |
| Discovery | arp-scan, Pi-hole, DHCP leases, UniFi, SNMP, plugins | arp-scan | Own multi-protocol scan + router client lists (17 brands) |
| Device identification | Vendor lookup | Vendor lookup | Vendor + mDNS/SSDP/SNMP/HTTP fingerprinting, optional AI |
| Open-port overview | — | — | ✓, with security report |
| Presence history & new-device alerts | ✓ | ✓ (48 h default retention) | ✓ |
| Uptime / service checks | — | — | ✓ (HTTP, TCP, ping) |
| Infrastructure sensors | Via plugins | Grafana via InfluxDB/Prometheus | SNMP, Proxmox, NAS, Docker built in |
| Notifications | Apprise (80+ services), NTFY, Pushover | Shoutrrr (Discord, Telegram, Ntfy, …) | E-mail digests with severity levels |
| Install | Docker-first; Linux, Home Assistant add-on, Unraid | Docker, .deb/.rpm/.apk, binaries | Docker, .deb, macOS package, Windows service |
| Built-in authentication | Password login (off by default) | — (external SSO recommended) | ✓ (token) |
Feature claims from the projects' own documentation and repositories, checked August 2026. Both projects move quickly; if we have something wrong, tell us and we will correct it.
Where DeviceShelf Server fits
DeviceShelf Server starts where both of these stop. It discovers devices with its own multi-protocol scan and by reading the client list of seventeen router brands, then identifies vendor and type from mDNS, SSDP, SNMP and HTTP signals rather than the MAC prefix alone. On top sit an open-port overview with a security report, uptime checks, infrastructure sensors (SNMP, Proxmox, NAS, Docker) and e-mail alerts with digests and severity levels — assembled, not assembled-by-you. It installs as Docker, .deb, macOS package or Windows service, needs no account, and keeps all data local. The server edition is part of the one-time licence, with desktop apps for macOS, Windows and Linux included.
If your need is presence alerts and nothing else, run one of the free tools above and be happy. The moment the question becomes "what is this device, and should port 23 really be open on it", the free tier of effort runs out — that is the job we built for.
See the server edition Also compared: Uptime Kuma
Questions people actually ask
What is the difference between NetAlertX and WatchYourLAN?
Both watch for appearing and disappearing devices. WatchYourLAN is deliberately small: one binary, arp-scan, history, notifications. NetAlertX is the feature-rich one: many discovery sources, workflows, plugins, 80+ notification services. Neither identifies devices beyond the MAC vendor, and neither scans ports.
Are they free?
Yes, both are open source and self-hosted: NetAlertX under GPL-3.0, WatchYourLAN under MIT.
Which one is easier to set up?
WatchYourLAN, by design: one container or package, a handful of settings. NetAlertX rewards more time with more capability.
Do I still need anything else?
That depends on whether "a new MAC appeared" is the answer you need or the beginning of your question. Identification, port exposure, uptime and infrastructure health are outside both tools' scope; that is the layer DeviceShelf Server, and heavier suites, add.
All product names, logos and trademarks are the property of their respective owners. Mention here is for identification and comparison purposes only and does not imply any affiliation or endorsement. Feature details are gathered from public sources and may change; if you spot something out of date, please let us know.