inSSIDer is a small and easy to use program for scanning radio band used by wireless networks (Wi-Fi). The main motivation of the authors of the program was the fact that the popular NetStumbler scanner no longer functions properly on the newer Windows Vista and Windows 7 systems and on the 64-bit version of Windows XP. The inSSIDer scans the 2.4GHz and 5GHz bands using the system's native APIs and displays the found networks with their basic data such as SSID, access point MAC address, channel, signal strength, RSSI, speed and type of security.

This data may be useful, for example, when determining the best channel for a new wireless network or when investigating the cause of interference. The program works with most GPS receivers, and found networks can be later exported in NS1 format (used by NetStumbler) and KML format (used by Google Earth).