Skip the cabinet – get an over-the-door shoe organizer

A 6-inch gap is too narrow for almost any shoe cabinet you can buy off the shelf, so don’t waste time hunting for one that fits.

Standard shoe cabinets are built at least 8–10 inches deep because most adult shoes need that much room. Even the “slim” ones from IKEA or Amazon are usually 7–8 inches. A 6-inch gap means you’re looking at flip-flops and ballet flats only – and even then, the cabinet door won’t close properly.

I’d look at over-the-door shoe organizers if that gap is next to a door. They’re designed to hang on the door itself and take essentially zero floor space. Or if the gap is between a wall and something else, consider a wall-mounted shoe rack that holds shoes sideways (