Get the Litter-Robot 4. For one to four cats under 25 pounds, it cleans the way the 5 does, with the same rotating globe, the same 3-pound minimum and the same scale that tells your cats apart, and it's about $700 on Amazon. It's the older box, so you get buttons and lights instead of a screen, and a drawer you empty a couple of days sooner.
The Litter-Robot 5 is worth the step up for a cat over 25 pounds, a fifth cat, or a box that has to stand on carpet. Whisker sells it, and the 5 Pro, only on its own site.
The short answer
Get the Litter-Robot 4 for one to four cats under 25 pounds. Get the 5 for a bigger cat, a fifth cat, or a box that sits on carpet.
Our pick for most homes
Litter-Robot 4
Get it if every cat is under 25 pounds and there are four or fewer. Same globe, same scale, and it's on Amazon.
The 4 is made for cats from 3 to 25 pounds and up to four in one home; the 5 goes to 30 pounds and five cats. The globe is the same 15.75 inches wide at the entry on both, with an inch more height inside the 5 (17.5 inches against 16.5). For a Maine Coon who has passed 25 pounds, or a fifth cat, the 5 wins; below that, the extra room changes nothing you'll notice.
The waste drawer
With one cat, the 4's drawer goes about 8 days between emptyings and the 5's about 10, by the maker's chart. Every extra cat shortens both. The 5 wins, by about two days per drawer.
On carpet
The 4 reads your cat's weight best on a firm floor, and on carpet 3 mm or thicker it wants its carpet tray, sold separately. The 5 has the tray built into its base and works on any floor. If the only spot for the box is a carpeted room, the 5 wins.
Pee or poop: WasteID
This is the 5's one new idea. Its WasteID sensors tell urine from stool, run the cycle soon after a stool and wait longer after urine so the clumps can set, and log each visit as one or the other in the app. It gets more accurate over the first 30 days or so. For a cat with a urinary or kidney problem whose vet wants her visits watched, that log is the reason to buy the 5. For a healthy cat, the 4's visit and weight log already does most of the job.
Size, weight and the screen
Both stand on 22 by 27 inches. The 5 is 0.4 inch taller and weighs 28.7 pounds empty against 24, which you'll feel the day you carry it upstairs. It has a color screen where the 4 has buttons and lights; both are run from the same Whisker app, so I wouldn't pay for the screen. On size, the 4 wins by a little.
What they do the same
Both sift clumping clay litter through a turning globe a few minutes after your cat leaves (you can push the wait to 30 minutes), weigh each cat, and keep seven days of visits and weights in the free app. Both start at 3 pounds; below that, the box runs by hand in semi-automatic mode. Both want a standard-weight clumping clay, never crystals, pellets or plant litters (the best litter for the Litter-Robot lists what each robot takes), and both come with a one-year warranty. The bags, filter and OdorTrap packs you keep buying are the same too.
The Litter-Robot 4, the 5 and the 5 Pro
Top pick
1Our pick
1. Litter-Robot 4
A quiet rotating globe that sifts after every visit and weighs each cat, for cats from 3 to 25 pounds.
Every cat in the house is under 25 pounds, there are four or fewer, and the box goes on a hard floor or a thin rug.
Skip it if
One of your cats is past 25 pounds and still growing, or a fifth cat shares the box.
The globe waits a few minutes after each visit, then turns and sifts the clumps into the drawer underneath, and the base weighs whoever just went. With two or more cats, the app sorts the visits by weight, so you see who went and how much each cat weighs. It's the one of the three you can order on Amazon, and the same box sits at the top of the best self-cleaning litter boxes.
Where it falls short
The globe is round and smaller inside than a long open box, so a very long cat has less room to turn.
On carpet 3 mm or thicker, plan on the carpet tray as well.
2Better for big cats
2. Litter-Robot 5
The same globe with a higher cat limit, a fifth cat, any floor, and a sensor that tells pee from poop.
Sold only by Whisker$799at Whisker, as of Oct 24, 2026See it at Whisker
Buy it if
You have a cat over 25 pounds, five cats, a carpeted floor, or a vet who wants to know how often your cat pees.
Skip it if
Your cats are average sized and the box sits on tile. You'd be paying for a screen and two days of drawer.
It's the 4's globe on the same footprint, a little taller inside, with WasteID added and a base that works on carpet. It takes cats from 3 to 30 pounds, up to five of them, and with one cat the drawer goes about 10 days. The three-year WhiskerCare plan costs a little more than the 4's.
Where it falls short
Sold only by Whisker, in the United States and Canada.
The WasteID log needs about a month of use before it's at its most accurate.
3Cats you'd rather tell apart by face
3. Litter-Robot 5 Pro
The Litter-Robot 5 with two cameras, one facing out to recognize each cat, one inside the globe.
Sold only by Whisker$999at Whisker, as of Oct 24, 2026See it at Whisker
Buy it if
Two or more of your cats weigh about the same and you want each visit tied to the right cat, by face.
Skip it if
You'd rather not pay a monthly fee, or your cats are easy to tell apart on a scale.
Everything in the 5, plus two cameras: one faces out and recognizes each cat, the other looks into the globe. Recognizing faces, unlimited live video and 30 days of recordings need the Whisker+ plan, about $8 a month after a 30-day trial; a year of it comes with the 5 Pro. Without it, you get five minutes of live video a day and two days of recordings.
Where it falls short
The camera features you'd buy it for sit behind the subscription after the first year.
Sold in the United States only.
Is the Litter-Robot 5 worth it?
Over a 4, only if one of its four changes fits your house: a cat over 25 pounds, a fifth cat, a carpeted floor, or a reason to track pee and poop apart. If you already own a 4 that works, none of them is a reason to replace it, since the cleaning is the same. And if the price of either is the problem, the best self-cleaning litter boxes under $200 start from a very different design, open trays and crystal boxes.
Litter-Robot 5 Pro vs 5
The Pro is the 5 with its two cameras, and the same limits: 3 to 30 pounds, five cats, about 10 days of drawer with one cat. The 4 and the 5 already tell cats apart by weight. A face does better when two cats weigh about the same, which is why the Pro makes sense mostly for three or more cats of similar size. For one or two cats of different builds, buy the 5, or the 4.
Litter-Robot 5 release date
Whisker announced the Litter-Robot 5, the 5 Pro and the EVO on October 21, 2025, and started shipping in the United States on November 3, 2025. Canada and other countries were set for 2026. The Litter-Robot 4 stays on sale beside them, on Amazon and at Whisker.
Which one to buy
One to four cats, all under 25 pounds
The Litter-Robot 4. It does everything that matters here, for less, and it's on Amazon.
A cat over 25 pounds, or a fifth cat
The Litter-Robot 5. It's the only one of the two made for either.
The box has to go on carpet
The Litter-Robot 5 works on any floor. The 4 does too with its carpet tray, bought separately.
A cat whose vet watches her urine
The Litter-Robot 5, for the WasteID log. Bring the log to the vet; it isn't a diagnosis.
Several cats the same size
The Litter-Robot 5 Pro, if you'll keep the Whisker+ plan.
For a cat who has started going next to the box, or an older cat stiff in the hips, start from cat litter and litter boxes, sorted by problem: the step into both globes is about 7 inches.
How I picked
Cat weight allowedNumber of catsDays between emptyingsThe floor it needsWhere you can buy it
Save it for laterPin this guide and find it again when you are ready to buy.Save to Pinterest
Common questions
What's the difference between a Litter-Robot 4 and 5?+−
The 5 takes cats up to 30 pounds instead of 25 and five cats instead of four, its drawer goes about 10 days with one cat instead of 8, it works on carpet without a tray, and it tells pee from poop in the app. It also has a color screen. The globe, the minimum weight and the footprint are the same.
Is Litter-Robot 5 worth the upgrade?+−
From a working Litter-Robot 4, rarely: the cleaning is the same. It's worth it for a cat who has outgrown 25 pounds, a fifth cat, or a vet who wants pee and poop tracked apart.
Why is Litter-Robot 5 not on Amazon?+−
Whisker sells the 5 and the 5 Pro on its own site, and the Litter-Robot 4 and the EVO are the ones you'll find on Amazon. Buying from Whisker also gets you its 90-day in-home trial.
Is the Litter-Robot 5 Pro worth it?+−
For three or more cats of about the same weight, and an owner who'll keep the Whisker+ plan after the first year, yes. For most homes, the scale in the 4 or the 5 already tells the cats apart.
What's the difference between Litter-Robot 5 Pro and Litter-Robot 5?+−
Two cameras, one facing out to recognize each cat's face and one inside the globe. The rest is the same box: same size, same cat limits, same drawer.
The verdict
The Litter-Robot 4 for most homes
One to four cats under 25 pounds, on a hard floor: the Litter-Robot 4. A Maine Coon past 25 pounds, a fifth cat or wall-to-wall carpet: the Litter-Robot 5, from Whisker.
