A WiFi mapper records the WiFi networks your device can hear along with where it heard them, then draws them on a map. WifiMapper does this with an Android app that scans as you walk and a web map that plots every sample by SSID, access point and signal strength.
No. An ordinary Android phone with WiFi and GPS is the whole kit. WifiMapper uses the phone's own WiFi radio for the readings and its GPS for the positions, so there is no survey adapter, spectrum analyser or external antenna to buy.
Never. It only listens to the beacons that every WiFi access point broadcasts publicly. It needs no WiFi passwords, joins nothing, and changes no router or controller settings - so mapping a network requires nothing from whoever runs it.
Yes, and it is one of the most common uses, but accuracy follows your GPS. In a single-storey building with windows, GPS is usually good enough to tell rooms apart. Deep inside a warehouse or a basement it will drift, so map at a slower walk and treat the positions as approximate. WifiMapper maps by GPS position, so it does not separate floors in a multi-storey building.
WifiMapper does not claim an exact position - it shows you the evidence. Samples are drawn as dots sized by signal strength, so the cluster of largest dots sits very close to the radio. In open ground that usually puts you within a few metres; through walls and floors, signal strength is distorted by what it passed through, so read it as a strong hint rather than a survey fix.
The SSID (network name), the BSSID (the access point's hardware address), the channel centre frequency, the signal strength in dBm, the security protocol, and the GPS position and time of the reading.
Because it genuinely is several radios. Every WiFi radio has its own BSSID, so a dual-band router appears as one access point for 2.4 GHz and another for 5 GHz, and each node of a mesh system adds more. That is what lets the map show which radio you are actually reaching from where you stand.
Yes. The free plan stores samples for your first 100 access points, with unlimited scans of those access points and full use of the web map. No card is needed to start, and you can upgrade to unlimited access points later from your subscription page.
Each distinct BSSID you upload counts once, no matter how many times you scan it. Scanning the same access point a thousand times still counts as one.
No. You see your own uploads. Your samples are scoped to your account and are not shown to other users.
Continuous scanning with GPS running does use power, as any mapping app does. Map in sessions rather than leaving it running all day, and expect a walk-length survey rather than a whole shift on one charge.
Recording the beacons that access points broadcast publicly is generally lawful in most places, and WifiMapper never connects to a network or reads anyone's traffic. Local rules and site policies still apply, so map where you are allowed to be and check with whoever runs a site before surveying it professionally.
Sign in and use the Contact menu to send us a message - we reply by email. Or just start a free account and try mapping a room.