Rotating drum~$699

Whisker

Whisker Litter-Robot 4

Name: Whisker Litter-Robot 4
Brand: Whisker
Price: 699 USD
Availability: InStock

Automate from ~3 lb / ~3 monthsAnti-pinch protectionRated for large breeds (to 25 lb)

Four years on, this is still the reference point everything else in the category gets measured against. Three curtain lasers across the bezel and a scale in the base decide when a cat has left, and anti-pinch sensors on both sides of the drawer chute stop and reverse the globe if something is in the way. Whisker rates it for cats from 3 to 25 lb and up to four of them, and it runs on ordinary clay clumping litter.

Approx. price

~$699

maker's store, not a live price

Kitten gate

3 lb / 3 mo

detects cats from 3 lb

Max. cat weight

25 lb

15.75-inch-wide entry

Running cost

No consumable

Runs on clumping litter from any brand the maker allows

Warranty

1 yr

standard, before extensions

Best for: Two or three average cats in a home that already uses clay clumping litter

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Kittens and small cats

Whisker says the sensor detects cats from 3 lb. At the usual rate of about a pound a month, that means leaving automatic cleaning off until roughly 3 months. Below the threshold, a kitten may not register at all, and the box could start a cycle with it inside.

Detection: weight, infrared / radar. The maker states anti-pinch protection on the moving part, by sensor or by design.

How minimum weights work, and what to do below them

Days between emptying

The maker publishes no drawer volume, so the days cannot be worked out. Its own claim is up to 8 days for one cat.

Specifications

Approx. price: ~$699
Type: Rotating drum
Kitten gate: Automate from ~3 lb / ~3 months
Min. detection weight: 3 lb
Max. cat weight: 25 lb
Big-cat fit: Rated for large breeds (to 25 lb)
Entry opening: 15.75 × 15.75 in
Entry step: 6.9 in off the floor
Interior height: 16.5 in
Footprint: 22 × 27 in × 29.5 in tall
Maker's drawer claim: Up to 8 days, one cat
Cats supported: Up to 4
Litter system: Clumping litter
Litters listed: clumping clay
Litters to avoid: tofu, clumping wood/pine, non-clumping, paper, pellets, silica crystal
Weight sensor: Yes
Anti-pinch protection: Stated by the maker
Infrared / radar: Yes
Camera: No
Wi-Fi app: Yes
Running cost: No required consumable
Bags / liners: Standard trash bag or Whisker's custom-fit drawer liners
Warranty: 1 year
First listed: 2022

Features

Three curtain lasers plus a weight scale for cat detection
Anti-pinch sensors on both sides of the waste chute
Cycle delay adjustable up to 30 minutes
Litter and drawer levels reported in the Whisker app
Works with standard trash bags

What it does well

Anti-pinch detection on the chute is documented by the maker, not implied
A 15.75-inch square entry is among the widest of the enclosed drums here
No proprietary litter, cartridge or tray: ordinary clay clumping litter and a kitchen bag work
Detects kittens from 3 lb, and Whisker's own FAQ explains a supervised manual mode for lighter ones
App reports drawer fill and individual cat weights without a subscription

What it gives up

Whisker publishes no drawer volume, only an 'about every 8 days for one cat' estimate
Needs 2.4 GHz Wi-Fi; 5 GHz networks are not supported
Plant-based, pine, pellet and white crystal litters are all on the do-not-use list
At 22 by 27 inches it wants a floor spot bigger than most ordinary boxes

The two lists above are drawn from the maker’s own pages, manuals and prices, not from owner reports. Where owner discussion has been read it appears in its own section below, so the two are never mistaken for each other.

What owners say

For many owners the Litter-Robot 4 does what it promises: the scooping stops, the drawer gets emptied roughly weekly, and the house stops smelling of litter. The complaints that do come up tend to trace back to setup, such as too little litter, a short cycle delay or a litter that smears, and to the minority of cats whose aim misses the litter bed.

The mechanism is simple, and one owner who has run eight units says it holds up. When it does go wrong the patterns are recognisable: cycles repeatedly interrupted, a drawer-full sensor that misreads, and smell creeping back when urine gets under or onto the liner. A number of owners in 2023 reported the box cycling with a cat inside, and one in 2024 believes it injured a cat; Whisker asked for details and replaced at least one unit, and owners point out the pinch sensor at the waste opening is a separate protection.

It suits most average cats, especially where someone is happy to keep the litter at the fill line and deep clean every few months. Owners of side-peeing cats, and people who want zero maintenance, are the ones who end up disappointed.

What owners like

When it works as designed, owners describe the smell simply going away: a household with five cats says its home does not smell of cats, and a two-cat owner could put their head in the globe and smell nothing
The routine settles into emptying the drawer about once a week and topping up litter, and owners who add the Litter Hopper describe little else to do
Long-term owners report few breakdowns; one who has run eight units for 18 cats says problems have been rare, and two say they never deep clean theirs, one of them a year in
Whisker's support replaces faulty units: one owner's whole robot was swapped over a persistent smell (which returned months later), another's after it cycled with a cat inside, and a third got a new bonnet out of warranty

Common complaints

A minority report the opposite on smell, sometimes within weeks, and the causes owners find are cycles interrupted so the drawer sits open, urine hitting the rubber liner, or a worn liner
Cats that pee against the side or stand high hit the liner rather than the litter; one owner of two or three years is considering going back to ordinary boxes over it, and another wishes the litter bed were larger
Clumps stick to the globe with some litters, short cycle delays or too little litter; owners fill to the line, try a different litter, and some just wipe the wall at each bag change
The drawer-full sensor can misread, reporting full when it is not; one four-cat owner recalibrated at least five times without fixing it and power-cycles the robot several times a day instead
In 2023 two owners posted that their LR4 started a cycle with a cat inside, and one commenter's informal poll, since deleted, drew 20 yes votes; Whisker asked for serial numbers and shipped one owner a replacement, and one commenter suspected a night-vision camera's infrared light confusing the curtain sensors. In 2024 another owner believes theirs injured a cat's leg, after watching it start a new cycle with a second cat still inside
The Whisker+ membership angered existing owners when it launched in late 2025; one owner said free history had been cut, while Whisker said no previously free LR3 or LR4 feature was being gated

Questions owners ask about the Whisker Litter-Robot 4

How hands-off is the Litter-Robot 4 really?

Owners typically empty the drawer about once a week, top up litter (or let a LitterHopper do it) and deep clean every few months. Some never deep clean; others with messy cats wipe it down weekly. It removes scooping, not all maintenance.

Why does my LR4 smell?

Owners trace it to cycles being interrupted so the drawer stays exposed, urine hitting the liner, a worn liner, or the litter. Fixing those usually helps; Whisker replaced one owner's unit over a persistent smell, though it came back after a few months.

Can the LR4 cycle with a cat inside?

It is designed not to, using curtain sensors and a weight scale. Several owners reported it happening in 2023 and Whisker asked each for their serial number; one owner in 2024 believes it injured a cat. The pinch sensor at the waste opening is meant to stop the globe if something is caught.

Why is litter sticking to the globe?

Usually the litter, too little of it, or a cycle delay too short for the clump to set. Owners keep litter at the fill line, try a longer delay or a different litter, and some wipe the wall down at each bag change.

Do I need the Whisker+ membership for the LR4?

No. The robot works without it. Whisker says no previously free LR3 or LR4 feature was gated and that the membership mainly adds cloud video and newer features; one LR4 owner still read it as history being cut when it launched in late 2025.

My cat pees over the edge. What can I do?

Owners fill the litter to the line and add a taller fence, from Whisker or an aftermarket maker. Cats that stand to pee or aim at the wall are the case the LR4 handles worst.