Start with your cats, not the box. Each automatic litter box has a minimum and sometimes a maximum cat weight for its safety sensors, and a rating for how many cats it serves. A box that does not detect a light kitten can cycle with it inside.
Our picks at a glance
From published specs and our sizing rules. Not lab tested.
- 1
Up to 4 cats
Whisker Litter-Robot 4 self-cleaning litter box
4 cats max
Check price on AmazonPaid link
- 2
Lower cost, multi-cat
PETKIT PuraMax 2 self-cleaning litter box
15 days per waste bin
Check price on AmazonPaid link
- 3
Kittens from 1 lb
Casa Leo Leo's Loo Too self-cleaning litter box
1 to 20 lb cats
Check price on AmazonPaid link
Then look at the waste bin and the litter it takes. Drum-style boxes (Litter-Robot, PETKIT, Casa Leo) sift standard clumping litter into a sealed drawer. The PetSafe ScoopFree uses disposable crystal litter trays instead.
Top picks, and why
Whisker Litter-Robot 4 self-cleaning litter box
- Wi-Fi
- Min cat weight 3 lb
- Wi-Fi app
- Cat weight tracking
+2 moreFewer
- Carbon filters
- Step and fence
Rated for up to 4 cats of at least 3 lb, app tracks waste, litter and cat weight. $500 to $1,000.
- Rated for up to 4 cats
- App shows waste drawer and litter levels
- Weighs your cat after each visit
- Cats must weigh at least 3 lb in Automatic Mode
- Scale reads best on a firm floor, not carpet
$500 to $1,000, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
PETKIT PuraMax 2 self-cleaning litter box
- Wi-Fi
- 76 L interior
- 7 L waste bin
- Cats 3.3 to 22 lb
+2 moreFewer
- 7 IR + 4 weight sensors
- 2.4 GHz Wi-Fi
76 L interior for cats 3.3 to 22 lb, 7 L waste bin rated up to 15 days. $250 to $500.
- 76 L interior for cats 3.3 to 22 lb
- 7 L waste bin, up to 15 days between empties
- 7.87 in low entry for older cats
- 2.4 GHz Wi-Fi only
- Not for kittens under 6 months or carpet
$250 to $500, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Casa Leo Leo's Loo Too self-cleaning litter box
- Wi-Fi
- 6 L waste drawer
- UV odor control
- About 30 dB
+2 moreFewer
- Radar + 4 weight sensors
- No subscription
Rated for cats 1 to 20 lb, sealed 6 L drawer with UV odor control, about 30 dB. $500 to $1,000.
- Rated for cats from 1 lb, so kittens qualify
- Sealed 6 L drawer with UV and carbon odor control
- About 30 dB, no subscription fees
- 2.4 GHz Wi-Fi only
- 1 year limited warranty
$500 to $1,000, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Compare every pick
Paid links: we earn a commission if you buy, at no cost to you. Amazon prices change often, so we show a range and link to the live price.
Multi-cat homes
For two or more cats, the waste drawer and the multi-cat rating matter most. Both boxes here identify cats by weight in the app, which helps you spot a change in one cat's habits.
Whisker Litter-Robot 4 self-cleaning litter box
- Wi-Fi
- Min cat weight 3 lb
- Wi-Fi app
- Cat weight tracking
+2 moreFewer
- Carbon filters
- Step and fence
Up to 4 cats, waste and litter level monitoring, carbon filters, step and fence included. $500 to $1,000.
- Rated for up to 4 cats
- App shows waste drawer and litter levels
- Weighs your cat after each visit
- Cats must weigh at least 3 lb in Automatic Mode
- Scale reads best on a firm floor, not carpet
$500 to $1,000, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
PETKIT PuraMax 2 self-cleaning litter box
- Wi-Fi
- 76 L interior
- 7 L waste bin
- Cats 3.3 to 22 lb
+2 moreFewer
- 7 IR + 4 weight sensors
- 2.4 GHz Wi-Fi
76 L interior, 7.87 in low entry, 7 IR and 4 weight sensors, 7 L sealed bin. $250 to $500.
- 76 L interior for cats 3.3 to 22 lb
- 7 L waste bin, up to 15 days between empties
- 7.87 in low entry for older cats
- 2.4 GHz Wi-Fi only
- Not for kittens under 6 months or carpet
$250 to $500, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Kittens and quiet rooms
Most drum boxes start at 3 lb or more. Casa Leo rates the Leo's Loo Too from 1 lb, with radar motion detection and four weight sensors to pause cleaning.
Casa Leo Leo's Loo Too self-cleaning litter box
- Wi-Fi
- 6 L waste drawer
- UV odor control
- About 30 dB
+2 moreFewer
- Radar + 4 weight sensors
- No subscription
1 to 20 lb cats, about 30 dB, no subscription fees, works with Alexa and Google Assistant. $500 to $1,000.
- Rated for cats from 1 lb, so kittens qualify
- Sealed 6 L drawer with UV and carbon odor control
- About 30 dB, no subscription fees
- 2.4 GHz Wi-Fi only
- 1 year limited warranty
$500 to $1,000, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Budget: disposable crystal trays
If you want to stop scooping without a drum and an app, the ScoopFree uses crystal litter in a disposable tray you replace every few weeks. Budget for replacement trays as an ongoing cost.
PetSafe ScoopFree Crystal Classic self-cleaning litter box
- Crystal litter trays
- 99% dust free
- Leak-protected tray
- 1 tray included
Disposable lidded crystal trays, 99 percent dust free, leak-protected lining. under $100.
- Disposable trays, lift out and toss
- Crystal litter is 99% dust free and low tracking
- Leak-protected tray lining
- Ongoing cost of replacement crystal trays
- No app or cat weight tracking
Under $100, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
The bottom line
From published specs and our sizing rules. Not lab tested.
- 1
Up to 4 cats
Whisker Litter-Robot 4 self-cleaning litter box
4 cats max
Check price on AmazonPaid link
- 2
Lower cost, multi-cat
PETKIT PuraMax 2 self-cleaning litter box
15 days per waste bin
Check price on AmazonPaid link
- 3
Kittens from 1 lb
Casa Leo Leo's Loo Too self-cleaning litter box
1 to 20 lb cats
Check price on AmazonPaid link
Frequently asked questions
How many self-cleaning litter boxes do I need for multiple cats?
Veterinary groups including the AAFP recommend one litter box per cat plus one. A self-cleaning box resets the litter after each visit, which is why makers rate them for several cats: up to 4 for the Litter-Robot 4. If cats avoid a shared box, add a second box.
What is the minimum cat weight for a self-cleaning litter box?
It depends on the model. The Litter-Robot 4 needs cats of at least 3 lb in Automatic Mode, the PETKIT PuraMax 2 is rated for 3.3 to 22 lb and not for cats under 6 months, and the Casa Leo Leo's Loo Too is rated for 1 to 20 lb. Use manual mode or a regular box until a kitten meets the minimum.
Are self-cleaning litter boxes safe for cats?
The drum boxes use sensors to pause the cycle when a cat approaches or enters. The PETKIT PuraMax 2 has 7 infrared and 4 weight sensors plus an anti-pinch entrance, and the Casa Leo uses radar motion detection and 4 weight sensors. Follow the weight limits, because the sensors rely on detecting the cat.
How often do you empty a self-cleaning litter box?
It depends on the drawer size and the number of cats. PETKIT says the PuraMax 2's 7 L waste bin lasts up to 15 days, and the Casa Leo drawer holds 1.5 gallons (6 L). The Litter-Robot 4 app shows the drawer level so you empty it only when needed.
What litter works in a self-cleaning litter box?
Drum-style boxes like the Litter-Robot 4, PETKIT PuraMax 2 and Casa Leo work with clumping litter, and Casa Leo recommends clumping clay. The PetSafe ScoopFree uses its own disposable crystal litter trays.
Can I put a self-cleaning litter box on carpet?
It is better not to. Whisker says the Litter-Robot 4 scale is most accurate on a firm surface, and PETKIT says carpet or mats can interfere with the PuraMax 2 sensors. Place it on a flat, hard floor.
Do self-cleaning litter boxes reduce odor?
Yes, mainly by removing waste after each visit and sealing it away. The Litter-Robot 4 uses carbon filters, the PETKIT PuraMax 2 has a sealed bin plus an N50 odor remover, and the Casa Leo combines a sealed drawer, bamboo carbon filters and UV odor control.
Are self-cleaning litter boxes loud?
They make a short motor noise during each cycle. Casa Leo lists the Leo's Loo Too at about 30 dB, roughly a whisper. Put any drum box where a cycle at night will not bother you.
Do I need a subscription for a smart litter box?
No for the boxes on this page. Casa Leo states there are no subscription fees for the Leo's Loo Too's essential smart features, and the Litter-Robot 4 and PETKIT apps show usage and cat weight. Ongoing costs are litter, waste bags and filters, plus crystal trays for the ScoopFree.
Is a self-cleaning litter box worth it?
It is worth it if daily scooping is the chore you want gone or you travel for a few days at a time. A 7 L bin like the PuraMax 2's can go up to 15 days between empties. The app's per-cat weight and visit tracking can also flag a health change early.
7 products are linked on this page. We have not lab-tested these products; picks are based on published specifications and our sizing rules. Amazon prices change, so we show a range and link to the live price. See our disclosure.
Size it for your home
Marcus Reed
Founder and Editor, CrunchYourDollars
Marcus Reed builds the sizing tools on CrunchYourDollars. He is a software engineer with a long-running PC hardware and power supply habit, which is where the watts, watt-hours and surge math on this site comes from. Product specs are pulled from manufacturer data sheets, electricity rates from the U.S. Energy Information Administration, and water chemistry rules from the Water Quality Association. He is not a licensed electrician or plumber: the tools show the math and the matching models so you can make the call, and anything involving your electrical panel should be checked by a licensed pro.
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