A free, standalone Wi-Fi scanning and diagnostics tool for Windows. Discover nearby networks, decode raw beacon frames, track signal history, and generate field-ready PDF reports — built for IT engineers and field technicians, no install required.
Everything a field engineer needs to explain "why is this Wi-Fi bad" with evidence, not guesswork.
SSID, BSSID, vendor, channel, band, width, RSSI, PHY type, security, and more — refreshed on an adjustable interval.
Full information-element table per access point — ID, length, raw hex, and human-readable decoding of HT/VHT capabilities, RSN cipher/AKM suites, and more.
RSSI-vs-time tracking per access point, plus 2.4GHz/5GHz channel occupancy charts to spot congestion and overlap at a glance.
One-click report with a network summary, per-AP detail pages, decoded beacon tables, host diagnostics (VPN, RAM), location, ISP, and live weather — ready to attach to a ticket.
Built-in printable troubleshooting checklist — technician, customer and device details, environmental conditions, RF checks, and throughput verification steps.
Single .exe file, no installer, no .NET runtime to install separately, no admin rights needed. Copy it to a USB stick and run it anywhere.
Live network scan with signal history and full beacon decode, plus per-band channel occupancy.
A built-in, printable checklist so a site visit covers every factor that affects Wi-Fi performance — not just signal strength. Fill it in on screen, tick items as you verify them, then print a signed record for the ticket.
Pick the build that matches your Windows installation. Not sure? Almost every PC made since 2010 is 64-bit — use the 64-bit build unless you know otherwise.
Verify your download hasn't been tampered with or corrupted: after downloading, run certutil -hashfile LlemonScanner-15.B1-win-x64.exe SHA256 (PowerShell/Command Prompt) and compare the result to the SHA256 value shown above for the file you downloaded.
Both builds are digitally signed (self-signed certificate, SHA256, timestamped). Windows SmartScreen may still show an "Unknown Publisher" warning on first run since this isn't a publicly trusted Certificate Authority signature — that's expected for a self-signed build. The signature and the SHA256 checksum above both let you confirm the file matches exactly what we published and hasn't been altered in transit.
Wi-Fi coverage isn't just "signal bars." llemonai WiFi Scanner surfaces the environmental and technical factors that actually determine performance.
| Factor | Why it matters |
|---|---|
| Temperature & humidity | Affects RF propagation and can stress AP/client hardware in enclosed spaces. |
| Device load & connected clients | More clients on a channel means more contention and lower effective throughput per device. |
| Interference | Overlapping channels and non-Wi-Fi RF noise directly reduce usable capacity. |
| Positioning & obstructions | Distance, walls, and line-of-sight change signal strength far more than most people expect. |
| Uplink throughput | A great Wi-Fi signal can't outrun a slow upstream connection — both need to be checked together. |