Subnetlens

Subnetlens is a local-first Windows desktop app for LAN discovery, network mapping, and IT troubleshooting. It helps IT admins, small businesses, MSPs, and home-lab users see what is on their network without deploying a cloud service or server stack. It scans and classifies devices, builds an interactive topology map, tracks open ports and service history per device, listens for mDNS and SSDP device activity in real time, and includes built-in tools such as ping, traceroute, DNS lookup, port scan, WHOIS, GeoIP, TLS checks, and HTTP header inspection. The free tier includes single-subnet network scanning, topology mapping, device inventory, and core diagnostic tools. Subnetlens Pro (one-time purchase) adds Radar monitoring, Prometheus metrics, scheduled scans, risk scoring, HTML reports, IP address management, webhooks, an encrypted credential vault, SNMP topology, an embedded terminal, and multi-network profiles. Scan data stays on the user's machine unless explicitly exported. The installer is code-signed by HELIOSOFT LTD and contains no adware, bundles, or third-party offers.