There are 2 hotels within Istanbul Airport. One is YOTELAIR on the air side and the other is YOTEL LANDSIDE on the land side.
Apart from these two, you have another option. Yes, it’s not a hotel, it’s just a sleeping cabin. But why shouldn’t we say that it is ideal for short rests? Its name is IGA SLEEPOD
Sleepods are located to the left of the elevators going down to Gates D on the air side of the international departures floor.
Cabins are priced hourly and different prices apply day/night