At KEF, stay airside—use lounges and cafés, as security and distance rule out short exits.
We recommend you stay airside: Keflavík Airport is far from Reykjavik, making short exits unrealistic.
A very limited nearby stop is possible only if timing aligns.
Plan around rest and unique experiences. Stay near the city center, enjoy geothermal pools, landmarks, and nearby viewpoints, and avoid tight schedules.