A platform bed is a bed frame with a sturdy base (either solid, metal, or slatted) that holds the mattress up. What makes a platform bed unique is that it doesn't require a box spring. So, once you buy it, it's ready to use — no need to purchase any extra accessories. A platform bed is a type of bed frame that supports your mattress without the need for a box spring. Unlike traditional bed frames, platform beds are closer to the ground, and typically lift your bed about 12 inches or more off the ground.