Litter-Robot 4 vs PETKIT Purobot Max Pro

Buy the Litter-Robot 4 if your cat is large or the box runs all year and you care what it costs — a 3 to 25 lb range, the biggest published entryway in the category and a lower power ceiling. Buy the PETKIT Purobot Max Pro if you want to know what you are buying: it publishes both capacity figures, 35 dB, a rated wattage and a full camera specification, and Whisker publishes none of those.

The real difference is what gets published

Six automatic-box comparisons on this site have run through Whisker, Neakasa, Casa Leo and PetSafe. PETKIT has not appeared in any of them, and reading its spec sheet explains why it should: it is the deepest published specification in the category, and it makes the gap in Whisker’s sheet impossible to miss.

Whisker does not publish a globe capacity or a drawer capacity for the Litter-Robot 4. Not a rounded figure, not an approximation — nothing. PETKIT publishes 76 L of interior space and an 8 L waste bin, and attaches a claim to the second one: up to 17 days without scooping for one cat.

That matters because capacity is the specification that determines the only chore a self-cleaning box leaves you. You cannot plan around a number that does not exist.

Where Whisker still wins

Where the cat decides it

Whisker publishes 3 to 25 lb. PETKIT publishes 3.3 to 22 lb. For most cats that difference is academic; for a Maine Coon, a large domestic shorthair or anything hovering near twenty pounds it is the end of the conversation, because one maker has put that cat outside the range it states for its own machine and the other has three pounds of headroom left.

At the small end PETKIT is more cautious and more specific: a 1.5 kg floor, plus a note that kittens under 1.5 kg or younger than six months are not recommended. That is a more useful sentence than a bare weight, and it is the sort of thing Whisker leaves you to infer.

The entry figures are where PETKIT has gone backwards. Whisker’s 15.75 by 15.75 inches is the size of the opening — 248 square inches, the largest published in the category, and the number that matters for a big cat turning around. The discontinued Purobot Ultra published the other useful quantity, a 265 mm entrance height — the step a cat has to make, and the number that matters for an older or arthritic one. For the Max Pro PETKIT publishes no entrance figure at all, only that the entrance is wide. Our large-cat page ranks the whole category on the first.

Footprint, height and the room

The camera, and what it is honestly for

PETKIT publishes a real camera specification: 1080p, a 210-degree field of view, IPX5, with one-way audio. In a multi-cat house the useful function is identification — which cat used the box, how often, for how long — and that is genuinely hard information to get any other way. PETKIT combines weight with facial-feature recognition precisely because weight sensing alone cannot tell two ten-pound cats apart.

Two things to be clear about. First, PETKIT positions its stool and behavior analysis as pre-screening, not diagnosis, and that framing is correct: anything it flags is a reason to telephone a vet, and the Cornell Feline Health Center is the place to read about what litter-box changes can mean. Second, this is a camera with a microphone in whatever room your litter box lives in, which is a decision about your household and not only about your cat.

The two machines

The Litter-Robot 4 is the one to buy for a big cat, a long ownership or a cat that needs room to turn around. The 15.75 by 15.75 inch entryway is the largest published opening in the category, the 3 to 25 lb range is the widest here, and the 6-15 W supply still makes it the cheaper of the two to run. Whisker also has the longest service history of anyone in this market. The honest cons: it publishes neither capacity figure, which is a remarkable omission at this price; no noise figure at all; the warranty is one year unless you pay for three; and it is the taller machine by 5.8 inches.

The PETKIT Purobot Max Pro is the one to buy if you want the machine that tells you about itself. 76 L of interior space and an 8 L bin with a 17-day claim behind it, 35 dB, twelve safety sensors, a three-stage odor system built around a sealed bin, and a real camera specification. It is also the shorter machine and the one that takes less floor, which decides a lot of placements. The honest cons: a 22 lb ceiling rules out large cats the Litter-Robot takes; a 24 W rating is still the highest published of any box on this site; PETKIT publishes no entrance height for this model and no warranty term at all, both of which the Ultra it replaced did publish; a camera in the litter box room is a privacy decision; and PETKIT has a shorter track record than Whisker on the thing that actually matters with an appliance, which is what happens in year three.

Deciding in one minute

1. Weigh the cat. Near or over 22 lb and PETKIT has excluded it itself. Buy the Litter-Robot.
2. Measure the height above the spot. 23.74 inches against 29.5 is the difference between under-counter and not.
3. Decide about the camera. Several cats makes it genuinely useful; a shared bathroom may make it unwelcome.
4. Check what is on the other side of the wall. A bedroom makes 35 dB the only published figure that helps you.
5. Count three years of electricity. About $43 of difference at the published ceilings, less in practice.

See the category

Our automatic litter box roundup ranks the whole field, running costs does this arithmetic for every machine on the site, and the worth-it page argues the case against buying either.