PETKIT PuraMax 2 vs Litter-Robot 4: which should you buy?
Buy the PETKIT PuraMax 2 ($300) if you have one or two cats: it costs $399 less than the Litter-Robot 4 ($699). Buy the Litter-Robot 4 if you have three or more cats or a cat over 20 lb. Only Whisker says how many cats (up to 4) and how heavy a cat (25 lb) its box is made for.
PETKIT PuraMax 2 vs Whisker Litter-Robot 4, feature by feature
“Not published” means the maker does not state it. One rule per row: a bigger figure wins (cat weight, days between emptying), a smaller one wins (smallest cat, floor space, height). Odor, app, litter, floor and sensors get no winner: makers and testers describe them in their own words.
| Feature | PETKIT PuraMax 2 | Whisker Litter-Robot 4 | Better |
|---|---|---|---|
| Cats it is for | not published | up to 4 | can't compare |
| Smallest cat | 3.3 lb | 3 lb | Whisker Litter-Robot 4 |
| Heaviest cat | not published | 25 lb | can't compare |
| Days between emptying, one cat | not published | 8 days | can't compare |
| Floor space, front to back | 21.18 in | 27 in | PETKIT PuraMax 2 |
| Height | 21.73 in | 29.5 in | PETKIT PuraMax 2 |
| Cat safety while it cycles | 11 safety sensors; the entrance stays open while it cleans | Lasers, weight sensors and anti-obstruction technology | no winner by rule |
| Odor | Sealed waste drawer and several deodorizing options | Sealed, carbon-filtered waste drawer | no winner by rule |
| App | PETKIT app for iPhone and Android | Free app: 7 days of visits and each cat's weight | no winner by rule |
| Litter | Most clumping litters, not crystal | Clumping litter; not non-clumping or newspaper litters | no winner by rule |
| Floor | Hard floors, not carpet, rugs or mats | A firm surface, not carpet | no winner by rule |
Which one should you buy?
Get the PETKIT PuraMax 2 if you have one or two cats and want to spend less. It has 11 safety sensors, an entrance that stays open while it cleans, a sealed waste drawer and an app, by what Cats.com’s testers and PETKIT report.
Get the Litter-Robot 4 if you have three or more cats or a cat over 20 lb. It is the only one of the two whose maker says how many cats it is for and how heavy a cat it takes.
Want a third box in the mix? Litter-Robot 4 vs PETKIT vs Neakasa adds the PETKIT Purobot Max Pro 2.
On Amazon the PETKIT PuraMax 2 was $300 and the Whisker Litter-Robot 4 $699 when we checked. That is $399 less for our pick.
App and Wi-Fi
PETKIT PuraMax 2
- Without the app: Control panel has a Clean Now function (press menu, then OK) that needs no app. (maker’s words)
Whisker Litter-Robot 4
- Without the app: Cleans itself after the cat leaves; a Cycle button starts a clean by hand. (maker’s words)
- Without internet: Still works as a self-cleaning box with no WiFi. (maker’s words)
See also: PETKIT PuraMax 2 vs Neakasa M1 Plus: which to buy.
Questions
Which is better for two or more cats? The Litter-Robot 4. Whisker says it is for up to 4 cats, and that two average-sized cats usually mean emptying twice a week. PETKIT does not say how many cats the PuraMax 2 is made for.
Which is better for a big cat? The Litter-Robot 4, on the numbers. Whisker rates it for cats up to 25 lb. PETKIT gives no top weight for the PuraMax 2.
Which is better for a small cat or a kitten? They are close. PETKIT says cats under 3.3 lb (1.5 kg) should not use the PuraMax 2. Whisker says kittens of at least 3 lb can use the Litter-Robot 4 in automatic mode.
Which controls odor better? Both have a sealed waste drawer. Cats.com's testers rated the PuraMax 2 for good odor control, and its testers noticed no Litter-Robot 4 odor unless the drawer was open. (cats.com)
Sources
Each maker’s own US pages; Amazon prices from Amazon’s product data on the date shown. How we work.
PETKIT PuraMax 2Our pick, price as of November 2, 2026
$300 at Amazon