Our verdict
Pick the SmartSpin for a 12 in entry, cats up to 25 lb and the freedom to use clumping or non-clumping litter. Pick the Litter-Robot 4 for a four-cat rating and established design.
The central trade-off
Litter. PetSafe says SmartSpin takes clumping or non-clumping litter; Whisker says Litter-Robot takes any clumping litter.
Cats. SmartSpin is built for cats up to 25 lb; Litter-Robot for up to 4 cats of at least 3 lb.
Bin. SmartSpin promises up to 2 weeks hands-free.
Side by side
| Specification | PetSafe ScoopFree SmartSpin | Whisker Litter-Robot 4 |
|---|---|---|
| Cats (maker) | Not stated by the maker | 4 cats |
| Cat weight (maker) | Not stated by the maker | 3 lbs |
| Litter (maker) | clumping litter | clumping litter |
| Waste bin lasts (maker) | Not stated by the maker | Not stated by the maker |
| Noise (maker) | Not stated by the maker | Not stated by the maker |
| Dimensions | 20.9"L x 18.9"W x 26.4"H | 24"L x 24"W x 31"H |
| Weight | 25 pounds | 24 pounds |
| Warranty | 1 Year Limited Warranty | WhiskerCare |
Values are the makers' published specifications. "Not stated" means the maker doesn't publish it.