Whisker Litter-Robot 4 review: This $700 self-cleaning litter box outperformed every other box we tested

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I love my cats, but I don't love scooping their litter boxes. In fact, I've been using automatic litter boxes for years, starting with both the Litter-Robots 2 and 3, to reduce the time I spend cleaning and improve litter box cleanliness for my cats. When Whisker sent me the Litter-Robot 4 to test in 2022, I was eager to see if the newest generation was worth the investment.

In addition to using the Whisker Litter-Robot 4 since 2022, I have also tested eight other boxes for our guide to the best self-cleaning litter boxes. For weeks, I took notes as my cats circled, dug, and did their business, and in the end, I selected Litter-Robot 4 as the best overall self-cleaning box. Sure, $699 is a lot to spend on a litter box, but this machine gets the job done. It automatically disposes of cat waste, sparing me from having to see or smell it, and it keeps my cats from stepping in it later.

The Litter-Robot 4 also has the best safety features of the best litter boxes I've tested. It cycles quietly and is thoughtfully designed for cats of all sizes and needs with a spacious interior for large cats and optional steps for felines with limited mobility. Plus, its smart features can help you monitor your cat's well-being. The box is available in white or black, and I have it in both colors, which were provided to me as review samples by the brand.

Design and specs

A self-cleaning litter box has two main jobs: It makes your life easier, and it keeps your cat's box more sanitary. The Litter-Robot 4 accomplishes these tasks with an auto-cycling globe that separates clean litter from waste and deposits clumps into a drawer below.

The Litter-Robot 4 improves on the brand's previous generations with an upgraded laser sensing system and an extra-large waste drawer with odor-locking technology. The third generation machine can recognize cats weighing 5 pounds or more, but the Litter-Robot 4's laser sensing system can recognize cats weighing at least 3 pounds. The larger, odor-reducing waste drawer requires less frequent emptying. 

This box has a very quiet cycle of about 33 decibels (dB). It's significantly quieter than the Litter-Robot 3 (48.7 dB) and our dust-free recommendation, CatGenie AI (51.4 dB). A difference of 15 dB is significant when you live in a small space or if, like me, you keep the litter box in a bedroom. For the sake of comparison, the sound of a whisper clocks in at about 25 dB. A suburban area at night is about 40 dB, and the hum of a refrigerator is about 55 dB. 

With a footprint of 22 inches wide, 27 inches deep, and 29.5 inches high, the Litter-Robot 4 is slightly slimmer than the Litter-Robot 3. Still, it's arguably large and requires placement next to a power outlet. Its most standout feature is the large circular entry of 15.75 inches in diameter. That, paired with its roomy interior, landed it a top spot in our guide to the largest litter boxes.

You can also use the machine's companion app to get real-time updates on your cat's usage. The app can tell you when the waste drawer is full, the amount of clean litter remaining, and how much your cat weighs when they enter the litter box.

Review of the Whisker Litter-Robot 4

The Litter-Robot 4 arrives almost fully assembled in a large box. I plugged it in, added our favorite clumping litter, and followed the step-by-step setup guide in the app. My cats had plenty of experience using the Litter-Robots 2 and 3, so they took to the new box right away. Insider Reviews senior reporter James Brains also tested the Litter-Robot 4, and his cats began using the automatic box exclusively after four days of encouragement.

I like that when I open the app, all my current Litter-Robot devices are visible, including our Litter-Robot Feeder. The home screen shows how full the waste drawer is, and with one click, I can check the weight of the last cat who used the box, when the box last cycled, and how much clean litter remains.

Because I have more than one litter box, I empty the Litter-Robot waste drawer roughly once a month and top off the clean litter even less frequently. The unit comes with a removable fence to prevent litter scatter, but for good measure, I pair it with Whisker's litter trap mat. 

The machine automatically cycles waste into its waste bin after every use. But our experts and the brand say every litter box requires an occasional deep cleaning. 

To deep clean the Litter-Robot, I press the "Empty" button on the unit panel to empty the litter into the waste drawer. Then I remove the approximately 8-pound globe and wash it with soap and water in the bathtub or outside with a hose. The brand recommends a deep clean every one to three months. If you notice waste sticking to the sides of the globe, like our tester Brains, I recommend deep cleaning more often.

One major way Whisker stands out from its competitors: You can reach a human in their customer service department. While I struggled to find phone numbers for other brands, I've spoken to customer service reps a few times about the faulty pinch detection in our Litter-Robot 3. (Rest assured, this is no longer an issue in the Litter-Robot 4.) Generally, the reps resolve any issues by accessing my machine's performance history and information, allowing them to quickly pinpoint the problem.

The cons

There's no denying that the Litter-Robot 4 is expensive. However, you have three months to return it if your cat doesn't want to make the switch. You'll just have to pay for shipping. The machine also comes with a one-year warranty covering accidental damage, power surges, mechanical and electrical breakdowns, and software support. If you need to send your unit back to Whisker for mechanical issues during the warranty period, the brand will cover shipping both ways. You also have the option to purchase an extended three-year plan for $100.

I haven't had to use my warranty for the Litter-Robot 4, but that doesn't mean it's perfect. For example, at one point the unit cycled whether a cat had used it or not. Whisker has since pushed a software update to fix the issue.  

You also need to place the unit on a hard surface (not carpet) to accurately weigh your cat. Whisker just released a Litter-Robot 4 Carpet Tray ($30), but our unit currently sits on a makeshift platform.

Brains also says he received cleaning notifications before they seemed necessary, but that the sensor resets when he shakes the drawer to distribute the waste more evenly.

What are your alternatives?

With all the bells and whistles it includes, the Litter-Robot 4 is a worthwhile smart home device. If you don't need a self-cleaning litter box with smart features, I recommend the Petsafe Scoop Free Self-Cleaning Litter Box, which is around $200 but often on sale for around $170. It uses a raking system, crystal litter, and disposable leak-proof trays.

If you prefer the smart features at a lower cost, you might consider the Litter-Robot 3, which ranks high in safety. 

And finally, if you want a self-cleaning box that requires very little maintenance, I recommend the CatGenie A.I. It uses washable, dust-free granules as litter and flushes waste into your wastewater system. You never have to empty waste bins, and you'll just need to deep clean it about every six months.

The bottom line

Despite its price tag and other minor drawbacks, the Litter-Robot 4 is the best self-cleaning litter box if you're looking for sophisticated features. I haven't had any tech issues with it, apart from a few ghost cycles and inaccurate weight tracking on carpet — issues the brand has since addressed. I especially like its feline-forward design and trustworthy safety features.

The Litter-Robot 4 is an investment designed for future software upgrades and add-ons. In August 2023, the brand notified users of a SmartScale update. The software is designed to recognize and track individual cats in multi-cat households by weight. Jacob Zuppke, the CEO of Whisker, told me the brand also plans to introduce AI behavioral learning and pet ID tags to track cats with similar weights. And if you're a current Litter-Robot 4 owner and haven't noticed the hidden USB port, take a look under the bonnet. You can use the Whisker camera mount to keep a closer eye on your cat.