Foil kites are soft kites based on the design of the parafoil. They consist of a number of cells running fore to aft, some or all of which are open at the front to allow air to inflate the kite so it takes on an aerofoil section. Due to the amount of power that these kites can generate, they can be used for a variety of different activities including kitesurfing, kite landboarding, snowkiting, kite buggying, kite-energy systems or airborne wind energy, and recreational kiting.
Foil kites are flown with various line set-ups that includes 2-, 3- and 4-line systems; 2-line systems consisting of rings, wrist bands or bar compared to depowerable 4-line systems using a bar or handles. (See also: kite control systems)
In order to make them suitable for use on water some foils have limited air inlets in the centre of the leading edge, with valves to keep the air in and (hopefully) the water out. Internal holes in the cell sides allow the whole kite to inflate. These kites are naturally slower to inflate than an open-fronted foil.
Foils are the most efficient of the power kites. The aerofoil section means that they can still provide significant lift when parked overhead, unlike leading edge inflatable kites.