# Instachew Purrclean vs Whisker Litter-Robot 4

As of Nov 4, 2026, the Instachew Purrclean costs $320 and the Whisker Litter-Robot 4 costs $699, so the Instachew Purrclean is $379 cheaper. The Instachew Purrclean has a published review score and ranks #8 in our self cleaning litter boxes ranking; the Whisker Litter-Robot 4 is not scored yet. Pick the Instachew Purrclean for small cats in small spaces. Pick the Whisker Litter-Robot 4 for one to four average size cats.

Prices checked Nov 4, 2026. HTML version: https://robotsforthat.com/vs/instachew-purrclean-vs-whisker-litter-robot-4/

## Side by side

| | Instachew Purrclean | Whisker Litter-Robot 4 |
|---|---|---|
| Price | $320 | $699 |
| 3 year cost | $320 | $1,035 |
| Our score | 7.3/10 | Not scored yet |
| Rank in Litter box | #8 | #23 |
| Status | on sale | on sale |
| Warranty | n/a | 1 year (WhiskerCare), extendable to 3 years; 90 day in home trial |
| Cat weight range | At least 2.5 kg (5.5 lb) and over 6 months (Chewy listing); no maximum published, reviewers say large cats do not fit | 3 to 25 lb (kittens under 3 lb need semi automatic mode) |
| Max cats | Not published; Cats.com found only 3 of 7 cats small enough to use it | Up to 4 |
| Waste drawer | About 8 L drawer with bag liner (Chewy listing) | Sealed drawer with carbon filter, as little as once every 8 days (maker claim) |
| Sensors | 12 safety sensors (Cats.com); infrared cat detection within 50 cm of the opening and a foreign object sensor (TechnoMeow) | Laser and weight sensors, SmartScale cat weight tracking, SafeCat system |
| App | Instachew Infinity app for schedules, cat weights and visit logs; 2.4 and 5 GHz Wi-Fi (TechnoMeow) | Whisker app (2.4 GHz WiFi); free 7 day view, Whisker+ optional |
| Litter type | Clumping litters including tofu, soil and mixed (TechnoMeow, Chewy) | Clumping clay recommended; crystals only if they pass the screen; plant based and pellet litters not recommended |
| Size | 19 x 20 x 26 in, 32 lb (TechnoMeow); inner 46 x 42 cm, entry 9 in off the floor (Chewy) | 22 x 27 in footprint, 29.5 in tall, 15.75 x 15.75 in entry, 24 lb empty |
| Noise | 47 dB (figure cited by TechnoMeow) | No dB rating published; QuietSift motor |
| Best for | small cats in small spaces | one to four average size cats |
| Skip if | you have cats over about 12 lb | your cat is over 25 lb |

## What reviewers found

### Instachew Purrclean

- Cats.com (3.6/5): Tested about six weeks in a seven cat home; only three cats were small enough, drum removal was awkward, app pairing was slow and nearby cats set off many alerts. [Source](https://cats.com/purrclean-smart-self-cleaning-litter-box-review)
- TechnoMeow (3.5/5): Tested on a friend's unit; a Siamese fit but a Bengal did not, the app disconnected often, some litter went unsifted and odors lingered. [Source](https://technomeow.com/instachew-purrclean-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 Instachew Purrclean or the Whisker Litter-Robot 4?

The Instachew Purrclean has a published review score and ranks #8 in our self cleaning litter boxes ranking; the Whisker Litter-Robot 4 is not scored yet. Pick the Instachew Purrclean for small cats in small spaces. Pick the Whisker Litter-Robot 4 for one to four average size cats.

### Which is cheaper?

The Instachew Purrclean at $320, versus $699 for the Whisker Litter-Robot 4, checked Nov 4, 2026. Over 3 years with running costs: $320 vs $1,035.

### What is the difference between the Purrclean and the Litter-Robot 4?

Cat weight range: At least 2.5 kg (5.5 lb) and over 6 months (Chewy listing); no maximum published… on the Purrclean, 3 to 25 lb (kittens under 3 lb need semi automatic mode) on the Litter-Robot 4. Max cats: Not published; Cats.com found only 3 of 7 cats small enough to use it on the Purrclean, Up to 4 on the Litter-Robot 4. Waste drawer: About 8 L drawer with bag liner (Chewy listing) on the Purrclean, Sealed drawer with carbon filter, as little as once every 8 days (maker claim) on the Litter-Robot 4.

Full reviews: [Instachew Purrclean](https://robotsforthat.com/robot/instachew-purrclean/index.md), [Whisker Litter-Robot 4](https://robotsforthat.com/robot/whisker-litter-robot-4/index.md)