The Litter-Robot 4 is a rotating sifting drum that uses clumping litter and drops clumps into a drawer below. The CatGenie AI+ takes a washing route: it needs a water supply and a drain, then repeatedly rinses and dries reusable granules.

The first installs anywhere with a socket and can be moved later. The second behaves like an appliance, needing water in, waste water out and power, so it usually stays in a bathroom or utility area; renters and frequent movers should check whether modification is allowed.

Cost structures diverge: the drum's spending is litter and liners, while the washing unit carries a higher upfront and installation cost plus cleaning solution and granule loss, amortised over years. Ingested granules and drain blockage are extra risks on the wet route.

Check whether the home has a suitable installation point and drainage, then judge how much washing maintenance you will really do. Multi-cat homes should look at cycle capacity per cat. For urinary cases, any automatic log is a lead only, and a veterinarian should confirm.