Every now and then I’m told by users of WiFi Explorer that the app does not detect “hidden” networks. Unfortunately, this is true. The CoreWLAN framework used by WiFi Explorer, and other similar apps in the Mac App Store, does not provide any information from networks that have been configured to not broadcast their SSID or network name. WiFi Explorer will, however, find and display the information of a hidden network if you’re connected to it, but if that’s not the case, nothing will be shown.
When you configure a network to hide its SSID, you are telling the router or access point not to announce the network name so client devices (e.g. your computer) can find it. As a result, your client device can only connect to the hidden network if you know and supply its SSID. This option, which comes as a standard feature in many routers, usually give users a sense of security, but here’s a tip: hiding the SSID won’t provide your network with any kind of protection. The truth is, the SSID is not really hidden.
There are many, and easy ways an attacker can discovery your SSID. In fact, because of how 802.11 wireless networks work, you can make matters worse by hiding the SSID since client devices that have previously connected to the network might constantly disclose the SSID, making things easier for an attacker. It might also result in increased connection times and can reduce the reliability of auto-connection features.
So, here’s my recommendation, keep broadcasting your SSID to the world and use WPA or WPA2 to secure your network.