Petkit PuroBot Ultra vs Whisker Litter-Robot 4
Researched by Riley Hart · prices checked Oct 26, 2026
As of Oct 26, 2026, the Petkit PuroBot Ultra costs $699 and the Whisker Litter-Robot 4 costs $699. The Petkit PuroBot Ultra has a published review score and ranks #9 in our self cleaning litter boxes ranking; the Whisker Litter-Robot 4 is not scored yet. Pick the Petkit PuroBot Ultra for health tracking with minimal handling. Pick the Whisker Litter-Robot 4 for one to four average size cats.
- Cat weight
- 3.3 lb and up
- Litter
- Clumping only
- Waste drawer
- Auto sealed bags
The PuroBot Ultra is for owners who want camera health logs and sealed waste bags they rarely touch. It is expensive, deep at 32.2 inches, and Cats.com found larger cats avoided it. Several features sit behind a subscription.
Full Petkit PuroBot Ultra review →- Cat weight
- 3 to 25 lb
- Max cats
- Up to 4
- Litter
- Clumping clay
- Waste drawer
- Sealed
A well tested globe box with a long track record and a large parts and support network, now $100 cheaper than the Litter-Robot 5. Owners of big cats over 25 lb, or anyone who wants urine vs stool detection, should look at the 5 instead.
Full Whisker Litter-Robot 4 review →Side by side
| Petkit PuroBot Ultra | Whisker Litter-Robot 4 | |
|---|---|---|
| Price | $699 | $699 |
| 3 year cost | $699 | $1,035 |
| Our score | 6.8/10 | Not scored yet |
| Rank in Litter box | #9 | #16 |
| Status | on sale | on sale |
| Warranty | 1 year (per Catster) | 1 year (WhiskerCare), extendable to 3 years; 90 day in home trial |
| Cat weight range | 3.3 lb and up (Catster) | 3 to 25 lb (kittens under 3 lb need semi automatic mode) |
| Max cats | Not stated; identifies cats by face, size and coat | Up to 4 |
| Waste drawer | Auto sealed bags, 14+ days for one cat (Catster) | Sealed drawer with carbon filter, as little as once every 8 days (maker claim) |
| Sensors | 20 sensors plus a rotating camera (Sam's Club listing) | Laser and weight sensors, SmartScale cat weight tracking, SafeCat system |
| App | Petkit app with live camera, two way talk and logs; full playback needs a Care+ plan | Whisker app (2.4 GHz WiFi); free 7 day view, Whisker+ optional |
| Litter type | Clumping only, clay or tofu; two sifters included | Clumping clay recommended; crystals only if they pass the screen; plant based and pellet litters not recommended |
| Size | 21 x 32.2 x 24 in, 32 lb (Catster) | 22 x 27 in footprint, 29.5 in tall, 15.75 x 15.75 in entry, 24 lb empty |
| Noise | n/a | No dB rating published; QuietSift motor |
| Best for | health tracking with minimal handling | one to four average size cats |
| Skip if | you have large cats or want no subscription | your cat is over 25 lb |
Specs are maker claims unless a reviewer is named. Prices from the stores we link, checked daily.
What reviewers found
Petkit PuroBot Ultra
- Cats.com (3.8/5): Six weeks of testing: scooping and sealing worked well, but larger cats would not use it, face recognition sometimes confused two cats, bags tore easily and litter leaked around the edges. Source
- Catster (4.9/5): Six weeks with one cat: no litter smell noticed, and the camera helped the tester spot a period of constipation; filling it with litter was awkward and there is no low litter alert. Source
Whisker Litter-Robot 4
- Cats.com: Runner Up in the October 2026 roundup; reliable and well built, but the smaller litter bed may not suit large cats. Source
- The Irish Times: Quiet, no smells and a clean tray in a home test; sensors stopped the drum when a cat entered; app cat ID was less accurate for cats of similar size. Source
- CNN Underscored: Drawer needed emptying about once a week with two cats; quieter than the Litter-Robot 3; cats took about a week to adjust. Source
Pros and cons
Petkit PuroBot Ultra
Pros
- Seals waste into bags automatically
- Camera helped a Catster tester spot constipation
- Strong odor control in two reviews
- Open front never fully closes
Cons
- Larger cats avoided it in Cats.com testing
- Face ID mixed up two cats at times
- Full playback needs a Care+ subscription
- Thin bags tore; no low litter alert
Whisker Litter-Robot 4
Pros
- Long track record and wide parts availability
- Laser plus weight sensing with SafeCat
- Free app weight tracking
- 90 day in home trial
Cons
- Smaller litter bed than the 5 series
- Fine grain clumping litter only, not tofu
- Early units had sensor complaints
- Bulky, needs a 22 x 27 in spot
Questions buyers ask
Which is better, the Petkit PuroBot Ultra or the Whisker Litter-Robot 4?
The Petkit PuroBot Ultra has a published review score and ranks #9 in our self cleaning litter boxes ranking; the Whisker Litter-Robot 4 is not scored yet. Pick the Petkit PuroBot Ultra for health tracking with minimal handling. Pick the Whisker Litter-Robot 4 for one to four average size cats.
What is the difference between the PuroBot Ultra and the Litter-Robot 4?
Cat weight range: 3.3 lb and up (Catster) on the PuroBot Ultra, 3 to 25 lb (kittens under 3 lb need semi automatic mode) on the Litter-Robot 4. Max cats: Not stated; identifies cats by face, size and coat on the PuroBot Ultra, Up to 4 on the Litter-Robot 4. Waste drawer: Auto sealed bags, 14+ days for one cat (Catster) on the PuroBot Ultra, Sealed drawer with carbon filter, as little as once every 8 days (maker claim) on the Litter-Robot 4.
Also consider
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- Petkit PuroBot Ultra vs Whisker Litter-Robot 5 Pro
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- Whisker Litter-Robot 4 vs Whisker Litter-Robot 5 Pro
All self cleaning litter boxes, ranked
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