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Litter-Robot 4 Review (We Tested It For a Month)

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Litter Robot 4 Review Feature

Mallory Crusta / Cats.com


  • Ease of Cleaning – 10/10
  • Odor Control – 10/10
  • Appearance – 10/10
  • Construction – 10/10
  • Price – 6/10

Overall Score: 9.2/10

After a month of in-home testing, the Litter-Robot 4 has proven its worth as a high-performing, more cat-friendly improvement on the previous Litter-Robot 3.

With a larger entryway, additional sensors that make it accessible to cats of all ages and sizes, and an improved app interface that gives you real-time updates on your litter and waste drawer level, the most significant changes to the Robot’s design revolve around cat-friendliness and ease of use.

Considering that these changes solve some of the most common complaints about the older model, this release demonstrates Whisker’s commitment to innovation and meeting users’ needs.

To understand how the new Litter-Robot 4 works and whether or not it’s worth it, I spent a month testing the unit with my two cats, Wessie and Forest. I took notes on how my cats responded to the design, how well the new sensor system worked, and how effectively it sifted.

In this review, I’ll share the details on the Litter-Robot 4, including my experience and analysis of whether or not the newest automatic litter box from Litter-Robot is worth the almost-$700 price tag.

Why You Should Trust Us

Litter Robot 4 Review Feature

Wessie, one of our product testing superstars, lounges next to the Litter-Robot 4. Mallory Crusta / Cats.com

Over the last three years, we’ve spent dozens of hours testing automatic litter boxes of every kind. Whether they spin, scrape, or flush, we’ve evaluated these automatic litter boxes’ performance in all key areas, including cat-friendliness, cleaning efficiency, odor control, affordability, and more.

In order to review the Litter-Robot 4, we spent hours researching the Litter-Robot brand and their newest automatic litter box model. And because hands-on testing is essential to fully understand how any product works, we also received a beta unit and spent over three weeks trying it in-home with two feline testers.

In total, over 100 hours of research and testing went into this review. Keep reading to get the details on the Litter-Robot 4 and find out whether or not I think it’s a smart choice.

Litter-Robot 4 Video Review

Now, let’s talk about how the Litter-Robot 4 works and how it’s different from the older Litter-Robot model.

LR3 and LR4

In the Litter-Robot 4, Whisker’s introduced several improvements upon the Litter-Robot 3 (left), most of them focused on sleeker design, better ease of use, and more cat-friendliness. Mallory Crusta / Cats.com

Whisker (formerly known as Auto Pets) has been leading the world of automatic cat litter box innovation since 1999, when founder Brad Baxter developed the first Litter-Robot.

This patented design had the same features we’ve come to associate with the Litter-Robot today—a rotating globe with a sifting mechanism that separates waste from clean litter and drops the clumps in a waste drawer at the bottom.

After the original Litter-Robot, the company created several subsequent models, including the Litter-Robot 2, Litter-Robot 3 Open Air, and eventually, the Litter-Robot 3 Open Air Connect, which added Wi-Fi and app integration to the system.

The company started developing its latest design in 2018, and after four years of development, the Litter-Robot 4 was announced on May 10th, 2022.

The Litter-Robot 4 builds upon the basic rotate-sift functionality of the original Litter-Robot and the Wi-Fi integration of the Litter-Robot 3 Connect with several cat-friendly, human-friendly improvements.

Here’s a summary of the most significant ones.

Litter-Robot 3 Litter-Robot 4
Footprint 24.25″ x 27″ 22’’ x 27’’
Inside Globe Size 15″-17″ H (depending on litter level) x 20″ W x 20″ D 15″-17″ H (depending on litter level) x 19″ W x 18″ D
Litter Bed Size 14” x 14” 14” x 14”
Entryway Size 10.25″ x 15.25″ 15.75’’ x 15.75”
Waste Drawer Size 5.00” H x 12.50” W x 16.00” D 5.50” H x 13.50” W x 9.25” D
Unit Weight 24 lbs 24 lbs
Minimum Cat User Weight 5 lbs 3 lbs
Maximum Cat User Weight None None
Sifting System Rotating sifting system Rotating sifting system
Cat Sensor System Weight-based cat sensor Laser-based cat sensor, weight-based cat sensor
Safety Features Pinch sensor, weight-based cat sensor Pinch sensor, laser-based cat sensor
Odor Control System Carbon filter in front of waste drawer Carbon filter on top of waste drawer, option to use OdorTrap
Cycling Noise Level 35 – 45 dB 25 – 35 dB
Cycle Timer Duration 3 – 15 minutes 3 – 30 minutes
Weight Tracking in App? No Yes
Litter Level Readouts in App? No Yes
Waste Drawer Fullness Readouts in App? Only full alerts Percentage full readout plus full alerts

It’s sleeker and more open for cat comfort.

Sleek Litter-Robot 4

Two inches narrower than its predecessor, the Litter-Robot 4 is a sleeker, slightly more subtle addition to the home. Mallory Crusta / Cats.com

While the litter bed still measures about 14” in diameter, and the globe is roughly an inch smaller on the inside, the design of the new Litter-Robot has several notable changes from the older model. It has a larger circular opening, measuring 15” in diameter, giving your cat more room to enter than the previous model’s oblong 15.5” x 10.25” opening.

It has a sleeker profile, measuring over 2” less in width than the Litter-Robot 3. With the buttons shifted to the top of the unit and the labels removed, the control panel takes on a sleeker, more modern appearance and no longer distracts from the space-age sleekness of the Robot’s front.

The new Litter-Robot 4 is available in a black or white shade.

It has a new sensor system.

With the Litter-Robot 4’s new sensor system, the unit is able to detect cats when they peek into—or step into—the box without activating the weight sensor. Combined with a pinch sensor, this makes it a safer choice for felines of all sizes. Mallory Crusta / Cats.com

While the previous Litter-Robot model relied on mechanical sensors, the new Litter-Robot 4 uses a combination of mechanical and laser sensors as part of what they call the OmniSense™ detection system.

With the new sensor system, the Robot is able to detect cats entering the litter box whether they’ve activated the weight sensor or not. No longer activated by cats weighing 5 lbs or more, it’s a safe option for adults and kittens alike.

When a cat enters the litter box, regardless of weight, it will start a timer if not already cycling. If it’s already cycling, the Litter-Robot will automatically stop and ensure that the cat isn’t caught. In addition to this sensor, the mechanical pinch detection system remains in place as a final safeguard for cats who might enter a cycling Litter-Robot.

Additionally, the Robot has integrated a new DFI sensor system, which enables reporting of small changes in the waste drawer’s fullness. In the app, this translates to a percentage-based readout that tells you exactly how full the waste drawer is at any time.

The app tells you more.

Litter Robot app

App updates have arrived for both the Litter-Robot 3 and Litter-Robot 4, but the LR4’s sensor system brings a new depth to the reporting available in the app. Mallory Crusta / Cats.com

On top of additional insights into the fullness of the waste drawer, the Litter-Robot 4 app gives you more information on what’s happening in the litter box and how your cat is using it.

Perhaps the most noticeable improvement is the addition of weight readouts, which help you to identify which cat has used the litter box. You can also monitor the litter level inside of the globe, adjust the night light’s brightness level, and control all of the settings you’re used to changing in the Litter-Robot app.

It’s engineered for better odor control.

Odor control module

With the carbon filter moved to the bottom of the base rather than the front of the waste drawer, the LR4 does a better job of sealing in odors and keeping your home fresh. Mallory Crusta / Cats.com

While the previous model of the Litter-Robot featured a carbon filter set in a grated area at the front of the waste drawer, the Litter-Robot 4 places the odor filter at the bottom of the globe, sitting right above the drawer. The carbon filter is encased in a simple plastic cage that can also contain Whisker’s OdorTrap™ packets if desired.

By sealing off the front of the drawer and positioning this odor control system overhead, the Litter-Robot 4 promises to keep waste drawer smells trapped.

It’s quieter.

Litter-Robot 4 sound level

With a cycling noise level between 25 and 40db, the Litter-Robot 4 is about as quiet as a whisper and significantly less distracting than the previous model. Mallory Crusta / Cats.com

With an average noise level of about 37 decibels while cycling, the new Litter-Robot 4 is about as subtle as a whisper, with most of the sound coming from the shuffling of litter rather than any motor noise. It’s, on average, 10 decibels quieter than the Litter-Robot 3, presenting a significant improvement for those who were disturbed by cycling during the night. The quieter operation may help shy cats to feel more comfortable around their new Robot as well.

Here’s my experience using the Litter-Robot 4 self-cleaning litter box.

Reading the note

The box came with a note from the company’s CEO and president. As you can see, Wessie was very enthusiastic about the new arrival. Mallory Crusta / Cats.com

While we normally independently purchase products for review, Litter-Robot offered a free Litter-Robot 4 beta unit for testing about a month prior to the launch, giving us the ability to try the Robot before it became available for purchase.

The delivery came wrapped in black plastic to hide the distinctive Litter-Robot packaging from view. Underneath was a large black-and-white box printed with Litter-Robot branding and the design of the new LR4. It included an introduction to the beta program and a note from Jacob Zuppke, Whisker’s president and CEO.

Inside, the Litter-Robot 4 was assembled and—almost—ready for use.

As with previous Litter-Robot models, the Litter-Robot 4 works best with a hard-clumping litter that resists humidity—this generally means that a clumping clay litter is the best choice.

Moister litter like clumping corn or cassava-based products will work as well, but there’s a greater chance that they will corrode metal components, including delicate sensors.

Non-clumping litter won’t break the box, but it doesn’t showcase the power of the system, as well as a clumping product, would.

I chose to use the all-natural premium clumping clay litter from Litterbox.com. This brand is owned by the creators of the Litter-Robot and offers excellent clumping performance that makes it a good match for the unit.

The Litter-Robot 4 cycled consistently and efficiently.

Litter Robot 4 cycling

While a few small particles managed to remain in the box after a cycle, I found that the Litter-Robot 4 efficiently cycled, not leaving behind a lot of clumps, chunks, or stuck litter. Mallory Crusta / Cats.com

Paired with that clumping clay litter, the Litter-Robot efficiently sifted through my cat’s waste. Whether they ran automatically, were triggered by a press of the button on the top, or were initiated from the Whisker app, each cycle occurred promptly and consistently.

I found that the Litter-Robot 4 worked well, sifting the clumps from clean litter without a lot of residue or sticking. Unlike other automatic litter boxes that use a raking mechanism to remove waste, the Litter-Robot’s rotating, sifting mechanism doesn’t tend to jam, and there’s not a lot of accumulation.

The waste drawer filled evenly, with most of the waste dropping to the center rather than building up on the side.

Though it is slightly smaller than the waste drawer of the previous model, the Litter-Robot 4’s drawer contains waste more evenly and might last slightly longer. Mallory Crusta / Cats.com

The waste drawer of the Litter-Robot 4 is slightly smaller than that of the Litter-Robot 3, but waste tends to collect in it more evenly compared to that of the older model, and Litter-Robot recommends that you change it out once a week with one cat and twice a week with two cats.

Thanks to the sensor that detects when the waste drawer is full, a blinking blue light panel on top of the unit and a notification from the Whisker app will let you know when it’s time to empty it out.

I found that, compared to the previous model, the sensor was much more sensitive, and the waste tray filled up all the way to the top before any notification appeared.

It controlled odors well.

With its filter positioned just above the waste drawer, I found that the Litter-Robot 4 did a good job of controlling odors. I didn’t notice any litter box odor until I opened up the drawer. Otherwise, the smells were completely contained.

I didn’t notice a lot of tracking or scatter, but the optional (included) fence can help.

litter scatter guard

The Litter-Robot 4 comes with a plastic fence intended to help contain scatter. Mallory Crusta / Cats.com

With only my smaller, more delicate cat, Forest, using the Litter-Robot 4, there wasn’t a lot of scatter or tracking around the unit. She tends to cover lightly and jump straight out, so she naturally didn’t throw much litter out, even with the larger opening.

The Robot’s step, with its ridged rubber mat, helps to contain any litter that’s tossed over the entryway, and I found that it managed to contain most of the granules that came out.

If you want some additional protection against scattering, the included Litter-Robot shield may help. I clipped it onto the front to see how it looked and worked, but I didn’t think my cats needed it and used the Robot without it for most of the trial.

What Did The Cats Think?

Forest in LR4

Forest refused to be photographed while using the Litter-Robot 4, but she’s a big fan of private moments in the Robot. She’s been using the Litter-Robot 3 since 2018 and readily took to the new model. Mallory Crusta / Cats.com

Only my smaller cat, Forest, was willing to use the Litter-Robot 4, while my larger cat preferred to use his regular open box. He’s not a fan of enclosed boxes in general, and he’s never been comfortable in the Litter-Robot, regardless of model.

With its open front, the design of the Litter-Robot 4 is more cat-friendly than the previous model, but it’s not perfect. The litter bed’s 14” diameter is still small, and the interior of the globe doesn’t provide much space for larger cats or any cat who doesn’t like feeling confined.

Most cats will prefer to use a basic open pan, but those like Forest—cats who don’t mind enclosed spaces and love having a perfectly-cleaned litter box at all times—may appreciate the constant clean of the Litter-Robot 4.

Using The Whisker App With The Litter-Robot 4

whisker app litter-robot 4

Now offering weight readouts in addition to use tracking, the Litter-Robot 4’s integration with the Whisker app gives you more information on your cat’s health and habits. Mallory Crusta / Cats.com

Drawing on the strength of the updated sensor system, the Whisker app provides additional insights into both your cat’s activity and the status of the box. The main screen shows you how much litter is in the box, how much waste is in the drawer, and how frequently your cats have been using the box. The weight readout tells you the latest measurement so you can assess your cat’s size over time.

Additionally, the app gives you all the basic controls you need, like the ability to start a cycle remotely, adjust the night light, lock the on-unit controls, and change the cycle interval between 3 and 30 minutes.

Overall, I found that the updated app was far more functional, consistent, and easy to use than the older version.

How Much Does The Litter-Robot 4 Cost?

The Litter-Robot 4 is available for preorder through the Litter-Robot website, and it costs $699—that’s $200 more than the older Litter-Robot 3 base model. Units start shipping out in July of 2022.

Overall, Is The Litter-Robot 4 Self-cleaning Litter Box Worth It?

For $699, the Litter-Robot 4 appears to offer the most advanced automatic litter box technology on the market, and the sensor upgrades, more open entrance, and superior odor control seem to make it a worthwhile upgrade from the Litter-Robot 3.

No automatic litter box is going to be the right choice for everyone, and if you balk at the idea of such an expensive device, I wouldn’t blame you. The vast majority of cats are happier in a well-scooped regular litter box, and for most of us, the time gained from scoopless days doesn’t add up to a nearly-$700-dollar benefit.

However, the investment could be worth it for some. If you can’t bring yourself to scoop daily, spend a lot of time away from home, or struggle with mobility, the Litter-Robot could be a good option. And considering the upgrades from the previous model, the new and improved LR4 is likely the best choice for 2022.

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About Mallory Crusta

Mallory is the Head of Content at Cats.com and an NAVC-certified Pet Nutrition Coach. Having produced and managed multimedia content across several pet-related domains, Mallory is dedicated to ensuring that the information on Cats.com is accurate, clear, and engaging. When she’s not reviewing pet products or editing content, Mallory enjoys skiing, hiking, and trying out new recipes in the kitchen. She has two cats, Wessie and Forest.

2 thoughts on “Litter-Robot 4 Review (We Tested It For a Month)”

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  1. Lyon Sara M

    Sounds great. I have three cats, 6, 13 & 7 years and have back issues. You don’t mention a word about cleaning the unit. Why not?
    I will wai a few months and get some more reviews.