# Petkit PuroBot Ultra vs Whisker Litter-Robot 4

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.

Prices checked Oct 26, 2026. HTML version: https://robotsforthat.com/vs/petkit-purobot-ultra-vs-whisker-litter-robot-4/

## 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 |

## 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](https://cats.com/petkit-purobot-ultra-automatic-litter-box-review)
- 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](https://www.catster.com/lifestyle/petkit-purobot-ultra-litter-box-review)

### 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](https://cats.com/reviews/best-self-cleaning-litter-box)
- 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](https://www.irishtimes.com/technology/consumer-tech/review/2026/10/03/litter-robot-4-review-fed-up-with-scooping-cat-litter-try-this/)
- 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](https://amp.cnn.com/cnn/cnn-underscored/reviews/litter-robot-4-review)

## 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.

Full reviews: [Petkit PuroBot Ultra](https://robotsforthat.com/robot/petkit-purobot-ultra/index.md), [Whisker Litter-Robot 4](https://robotsforthat.com/robot/whisker-litter-robot-4/index.md)