Novel solutions are required to connect bil-lions of devices to the network as envisioned by the IoT. In this article we propose to use LiFi, which is based on off-the-shelf LEDs, as an enabler for the IoT in indoor environments. We present LiFi4IoT, a system which, in addition to commu-nication, provides three main services that the radio frequency (RF) IoT networks struggle to offer: precise device positioning; the possibility of delivering power, since energy can be harvested from light; and inherent security due to the prop-agation properties of visible light. We analyze the application space of IoT in indoor scenarios, and propose a LiFi4IoT access point (AP) that commu-nicates simultaneously with IoT devices featuring different types of detectors, such as CMOS cam-era sensors, PDs, and solar cells. Based on the capabilities of these technologies, we define three types of energy self-sufficient IoT “motes” and analyze their feasibility. Finally, we identify the main research directions to enable the LiFi4IoT vision and provide preliminary results for several of these.