When the Internet is out, the switches function as a normal light switch. The switches respond to your physical touch but they can not be controlled by the mobile app. The one exception to this is with multi-way switches. With our technology, in 3-way / multi-way setup, only one switch actually controls the power to the lights / device being switched. The other switches simply take power to connect to the WiFi and send a signal to the main switch to toggle on or off. If the Internet is out, the signal will not make it from these switches to the switch that controls the lights / device so only the one master switch will respond to your physical touch when the Internet is out.