Litter-Robot 4 vs PETKIT vs Neakasa: which should you buy?
Buy the Whisker Litter-Robot 4 if you have two or more cats. It is the only one of the three whose maker says how many cats it takes: up to 4. For one cat, get the PETKIT Purobot Max Pro 2. It costs $491, and its drawer lasts the longest, 17 days. PETKIT does not say how many cats it is for, so we do not judge it for two. For a very small or very big cat, or one that will not walk into a drum, get the open-top Neakasa M1 Plus, rated for cats of 2.2 lb to 33 lb. Want to spend less? See our Litter-Robot alternatives.
For a house with 2 cats on clumping litter, buy the Whisker Litter-Robot 4. It is the only one of the three whose maker states a cat count, and both cats sit inside every limit Whisker publishes. The PETKIT Purobot Max Pro 2 and the Neakasa M1 Plus both come back "Maker does not publish the limit": the cats fit their weight ranges, but neither maker says how many cats the box is for.
Pick by what matters most to you. Fewest trips to the bin: the PETKIT, at 17 days for one cat. Lowest step in: the Litter-Robot 4, at 6.9 in. Heaviest cat or a cat that avoids drums: the open-top Neakasa, rated to 33 lb. A written cat count: only the Litter-Robot 4. A blank is not a zero and not a pass; the page does not fill one in.
| Model | Cats, up to | Cat weight, from | Cat weight, to | Drawer lasts, one cat | Step height | Litter | Warranty | Fit | Price | |
|---|---|---|---|---|---|---|---|---|---|---|
| Our pick |  Whisker Litter-Robot 4 | 4 | 3 lb | 25 lb | 8 days | 6.9 in | clumping | 1 year | Clears the published limits | $699 at Amazon |
| Not judged here |  PETKIT Purobot Max Pro 2 | not published | 3.3 lb | 22 lb | 17 days | 10 in | clumping | 2 years | Maker does not publish the limit | $491 at Amazon |
| The open top |  Neakasa M1 Plus | not published | 2.2 lb | 33 lb | 14 days | 13.9 in | clumping | 2 years | Maker does not publish the limit | $380 at Amazon (with 2-year protection plan) |
Who this is for
Read on if you have narrowed it to these three brands and want the makers' own figures side by side. If you have more cats than this house, start with The best automatic litter box for multiple cats, which checks every box we track.
Against the same house
The house is two cats, the heaviest 14 lb and the lightest 8 lb, on clumping litter. Whisker answers all of that in writing for the Litter-Robot 4: cats from 3 lb to 25 lb, up to 4 of them, on clumping litter. Both cats sit inside every limit, so it clears.
The Neakasa M1 Plus takes cats from 2.2 lb to 33 lb on clumping clay, and the PETKIT Purobot Max Pro 2 takes 3.3 lb to 22 lb on clumping litter. Both cats fit both. Neither maker states a cat count, so the page cannot clear them for two cats. Put your own cats and litter in the adjust box below; it re-checks the models here against your house.
Adjust to your house. Change the numbers and this box re-judges the models compared here against your house, with the same rules and the same maker figures. The picks and tables above stay on the page’s own house.
Our pickWhisker Litter-Robot 4
Our pick for two cats: every limit published
$699 at Amazon, November 2, 20264 cats, up to3 lb cat weight, from25 lb cat weight, to8 days drawer lasts, one cat
The Whisker Litter-Robot 4 is rated for cats from 3 lb to 25 lb and for up to 4 cats, on clumping litter, with no subscription needed to run it. Of the three makers, only Whisker states a cat count, so it is the only box this page can check against a two-cat house. It is also the biggest and the dearest: 22 in by 27 in on the floor, 29.5 in tall, and $699 when we checked. Its step in is the lowest of the three at 6.9 in, against 13.9 in for the Neakasa and 10 in for the PETKIT.
Price as of November 2, 2026; the listing we verified as the bare unit. Sold by Spreetail when we checked; we could not confirm whether that seller is an authorized dealer for the maker's warranty, so check before you buy.
What you give up
Price, the shortest drawer rating and the shortest warranty. Whisker rates the drawer at 8 days for one cat, against 14 days for the Neakasa and 17 days for the PETKIT. The warranty is 1 year, against 2 years from both PETKIT and Neakasa. A cat also has to step into an enclosed drum over the highest rim here. If that is the sticking point, the open-top Neakasa costs less.
Owner reports, tester figures, more photos and the listings we skipped are on the Whisker Litter-Robot 4 page. Figures from whisker.com. Recall screen: no US or Canada recall names this model, checked November 2, 2026.
Not judged herePETKIT Purobot Max Pro 2
Costs less, empties least often
$491 at Amazon, November 2, 20263.3 lb cat weight, from22 lb cat weight, to17 days drawer lasts, one cat
PETKIT states a cat-weight range of 3.3 lb to 22 lb for the PETKIT Purobot Max Pro 2, a drawer that lasts 17 days for one cat (the longest of the three), a step in of 10 in (in the middle of the three), and a size of 25.9 in by 21.2 in, 23.7 in tall. It takes clumping litter and carries a 2 years warranty. What PETKIT does not state is how many cats it is for, so this page cannot say it suits two. It was $491 on Amazon when we checked, against a $550 list price.
Price as of November 2, 2026; the listing we verified as the bare unit. Sold by PETKIT-US, the maker's own storefront, when we checked.
Owner reports, tester figures, more photos and the listings we skipped are on the PETKIT Purobot Max Pro 2 page. Figures from petkit.com. Recall screen: no US or Canada recall names this model, checked November 2, 2026.
The open topNeakasa M1 Plus
Open top, heaviest cats
$380 at Amazon, November 2, 20262.2 lb cat weight, from33 lb cat weight, to14 days drawer lasts, one cat
The Neakasa M1 Plus is the only open top of the three: a cat that will not walk into a drum has somewhere to go. Neakasa rates it for cats from 2.2 lb to 33 lb, the widest range here, with a 11.2 L bin that lasts 14 days for one cat. Neakasa says it works best with fast-clumping clay litter. It measures 22.8 in by 19.7 in and stands 26.8 in tall. Like PETKIT, Neakasa does not state a cat count. On Amazon it is sold with Neakasa's 2-year protection plan, at $380 when we checked; its own warranty is 2 years.
Price as of November 2, 2026. Amazon sells this unit only as the maker’s own listing with 2-year protection plan, so the price is for that listing. Sold by Neakasa official, the maker's own storefront, when we checked.
Owner reports, tester figures, more photos and the listings we skipped are on the Neakasa M1 Plus page. Figures from neakasa.com. Recall screen: no US or Canada recall names this model, checked November 2, 2026.
The 4 Litter-Robot 4, PETKIT and Neakasa models compared here, against that house
| Model | Verdict | What decided it |
|---|---|---|
| Whisker Litter-Robot 4 | Clears the published limits | cat weight limit is 25 lb; you need 14 lb whisker.com; minimum cat weight is 3 lb whisker.com; rated for up to 4 cats whisker.com; works with clumping litter whisker.com |
| PETKIT Purobot Max Pro 2 | Maker does not publish the limit | the maker does not say how many cats it is rated for |
| PETKIT Purobot Ultra | Maker does not publish the limit | the maker does not say how many cats it is rated for |
| Neakasa M1 Plus | Maker does not publish the limit | the maker does not say how many cats it is rated for |
One more PETKIT sits in the tables without being a pick: the Purobot Ultra. It is here because anyone comparing PETKITs will meet it, and it is not a pick because the page cannot judge it against this house either. It is also the only Purobot anybody has lived with in a review we can cite. Katelynn Sobus ran it hands-on for cats.com for over six weeks and came away positive about the experience but not the price: facial-recognition mix-ups and a shallow stool check-up feature left it, in her verdict, not worth the hefty price tag. Cats.com scored it 3.8 out of 5 overall.
Side by side, from the makers’ own documents
“Not published” means the maker does not state it. Prices are Amazon’s when we checked; “list” is the maker’s price. How to read these tables.
| Model | Cats, up to | Cat weight, from | Cat weight, to | Drawer lasts, one cat | Waste drawer | Litter | Subscription required | Warranty | Price |
|---|---|---|---|---|---|---|---|---|---|
| Whisker Litter-Robot 4 | 4 | 3 lb | 25 lb | 8 days | not published | clumping | no | 1 year | $699 |
| PETKIT Purobot Max Pro 2 | not published | 3.3 lb | 22 lb | 17 days | not published | clumping | not published | 2 years | $491 list $550 |
 PETKIT Purobot Ultra | not published | 3.3 lb | 22 lb | 20 days | not published | clumping | no | 2 years | $800 list $900 |
| Neakasa M1 Plus | not published | 2.2 lb | 33 lb | 14 days | 11.2 L | clumping | not published | 2 years | $380 with 2-year protection plan, on Amazon |
Minimum cat weight (maker’s stated number)
The lightest cat each maker says its box is built for, in the maker’s own words. Maker pages checked September 29, 2026. A maker’s minimum is not a safety rating. For every box we track, see automatic litter boxes for kittens and small cats.
| Model | Minimum cat weight | Maker’s words | Source |
|---|---|---|---|
| Whisker Litter-Robot 4 | 3 lb | “Litter-Robot 4 is designed for cats 3-25 lbs, and works for kittens and large breeds.” | whisker.com |
| PETKIT Purobot Max Pro 2 | 3.3 lb | “We do not recommend using PUROBOT MAX PRO 2 for kittens or cats weighing less than 3.3 lbs (1.5 kg).” | petkit.com |
| PETKIT Purobot Ultra | 3.3 lb | “Cat Weight Limit: 3.3 - 22 lbs (1.5-10 kg)” | petkit.com |
| Neakasa M1 Plus | 2.2 lb Its Amazon listing says 3.3 lb: “Supports cats from 3.3–33 lbs and up to 3 cats. For kittens under 3.3 lbs, enable Kitten Mode in the Neakasa App for safer use.” We use the higher number, 3.3 lb. | “Cat Weight Limit 2.2 lbs - around 33 lbs” | neakasa.com |
Buying it right
Each brand sells more than one box under nearly the same name: Whisker sells the EVO next to the Litter-Robot 4, PETKIT's Purobot line runs to Max Pro, Max Pro 2, Max 3 and Ultra, and Neakasa sells an M1 Plus Lite next to the M1 Plus. We link the listing whose own title names the brand and the full model. Neakasa sells the M1 Plus on Amazon only with its 2-year protection plan, so that is the listing we link for it, and the button says so.
Each model page lists the similar Amazon listings we did not link and why: Whisker Litter-Robot 4, PETKIT Purobot Max Pro 2, Neakasa M1 Plus. How we match listings.
What this page can’t promise
Side by side means side by side on what the makers publish. An empty cell is not a failing grade and not a pass: PETKIT and Neakasa may well suit two cats, but neither says so in writing.
Nothing here was tested by us. Measured figures and review scores belong to the testers named beside them, and the complaints are owners' reports. Neakasa's two-year warranty covers units bought since the start of this year; PETKIT's covers units bought since the start of last year.
A drawer figure is a maker's number for one cat of its own chosen size on its own chosen litter, and the page cannot know your cats, your litter or how much of the day they are home.
See also: Neakasa M1 Plus vs Litter-Robot 4: which to buy.
See also: PETKIT PuraMax 2 vs Neakasa M1 Plus: which to buy.
Questions people ask
Can the PETKIT or Neakasa handle three cats?
Neither maker says. Whisker states up to 4 cats for the Litter-Robot 4; PETKIT and Neakasa do not state a cat count for their boxes at any number. Either box may handle three cats. This page will not say so for them.
Is the PETKIT a worse box because the page cannot judge it?
No. The verdict describes what PETKIT has published, not how the machine works. PETKIT states a weight range, a size, an entry height, a drawer rating and a warranty for this model. It does not state how many cats it is for, and the page will not guess that number for it.
Does any of them need a subscription?
No box here needs one to clean. Whisker states the Litter-Robot 4 cycles with no subscription; its paid Whisker+ tier adds longer history. PETKIT's manual puts full camera video for the Purobot Max Pro 2 behind its paid Care+ tier, and the bin takes PETKIT's own bags. Neakasa's FAQ says any bag that fits the M1 Plus's drawer will do.
Which one is quietest?
Only Neakasa publishes a noise figure, 50 dB. Cats.com measured the Whisker Litter-Robot 4 while it was cycling, and that figure sits under the pick above with the tester named; a tester's measurement and a maker's claim are not taken on the same basis, so the two do not belong in a straight comparison. For the PETKIT Purobot Max Pro 2 there is nothing, and the nearest hands-on account of any Purobot, cats.com's six weeks with the Purobot Ultra, carries no noise figure we can quote. On PETKIT, your own room is the only test.
What if a cat refuses to use it?
Owners report that it happens. Cats.com's review of the earlier Neakasa M1, the box the Plus replaced, describes a cat that refused it outright and seemed to be in pain near it, whose owner went back to the old tray, while other cats took days to settle. So the return window matters more than any spec here. Whisker ships the Litter-Robot 4 with an in-home trial and refunds the purchase price, with the owner paying return shipping. PETKIT and Neakasa publish no return terms we can quote.
Does the drawer rating hold up for two cats?
Not for two cats at the one-cat figure. All three makers publish a one-cat rating: 8 days for the Whisker, 14 days for the Neakasa and 17 days for the PETKIT. Halve each for two cats as a rough guide. That halving is ours, not a maker claim.
Can I use crystal litter in these?
Whisker names clumping clay for the Litter-Robot 4 and warns that crystal and other white litters throw off its sensors. PETKIT says the Purobot Max Pro 2 works with most clumping litter. Neakasa says the M1 Plus works best with fast-clumping mineral or bentonite clay. So all three makers point you to clumping clay, not crystal.
Related pages
Whisker Litter-Robot 4Our pick
$699 at Amazon