Litter Robot 4 vs Litter Robot 3 (COMPARISON and Differences)

lr 3 or 4
(Last Updated On: November 16, 2023)

As any pet owner knows, dealing with pet waste can be a huge hassle. With your cat, there’s always going to be some sort of mess to clean up. But what if there was a way to make the whole process a lot easier? Enter the Litter-Robot. This self-cleaning litter box is designed to make your life a whole lot easier. But which litter-robot models are the best? Litter-Robot 3 or the new Litter-Robot 4? We’ve put together a detailed comparison to help you decide which popular robot cat litter boxes is right for you.

Compare Litter Robot 3 vs 4: Crucial Differences and New Features

FeatureLitter Robot 4Litter Robot 3
Size27" L x 22" W x 29.5" H
27" L x 24.5" W x 29.5" H
Weight24 lbs24 lbs
Multiple CatsGreat for up to 4 catsGood for up to 3 cats
Full Drawer IndicatorYesYes
Self CleaningYesYes
MaterialStrong, durable and easy-to-clean plasticStrong, durable and easy-to-clean plastic
Sleep ModeYes. Choose your own schedule.Fixed at 8 hours
Night LightAuto, On and Off. Choose High, Medium or Low.Auto and Off
WhisperQuiet Cleaning CycleYesNo
Cat Litter IndicatorYesNo
App ConnectivityNoOnly if you purchase Open Air
SensorsSmartScale Sensor and Curtain SensorWeight sensor only
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If you are in the market for an automatic litter box, you may be wondering if the Litter-Robot 4 is worth the extra money over the Litter-Robot 3. Let’s have a closer look at their differences.

LR4 is the newest model of automatic litter box from Litter-Robot. It is a step up from the Litter-Robot 3 in terms of features. The Litter-Robot 4 comes with a new self-cleaning mechanism that maintains hygiene in the litter box more efficiently than its predecessor.


Another benefit is that it has a bigger capacity than the Litter Robot 3. It can hold up to 20 lbs of litter, compared to the Litter Robot 3’s capacity of only 14 lbs. This means that you won’t have to empty the litter box as often, and it’s great for households with multiple cats. This means that it can hold more litter and waste, which is ideal for homes with multiple cats.

Litter-Robot 4 is great for up to 4 cats, while LR3 is better for up to 3 or two cats.

Better Sensors

The sensor on the LR3 is a lot more basic. It has a weight scale sensor that activates the system when your cat steps on. With the LR4, however, you get 2 sensors. The Smart Weight Scale sensor can sense your cat in the machine and record its weight. The Curtain sensor is positioned at the entrance of the machine and can sense your cat entering. With these 2 sensors working together, LR4 activates and works even more safely than before.

Minimum Size Of Cats That Can Use Each

litter robot after unboxing unpacking

While the Litter-Robot 4 is suitable for a maximum of 4 cats and the Litter-Robot 3 is suitable for a maximum of 3 cats, keep in mind that there is a weight minimum for each litter box for its sensors to best detect the cats. 

For the Litter-Robot 4, the minimum weight a cat needs to be in order to use the LR4 properly is 3 pounds. The LR4 can support cats that weigh more than this minimum.

For the Litter-Robot 3, the minimum weight a cat needs to be in order to use it properly is 5 pounds. Based on this weight minimum, the Litter-Robot 4 is better suited for smaller cats and kittens.

Better Sensors

The sensor on the LR3 is a lot more basic. It has a weight scale sensor that activates the system when your cat steps on.

With the LR4, however, you get 2 sensors. The Smart Weight Scale sensor can sense your cat in the machine and record its weight. The Curtain sensor is positioned at the entrance of the machine and can sense your cat entering. With these 2 sensors working together, LR4 activates and works even more safely than before.

Noise Level

LR4 boasts a special WhisperQuiet function. It’s a patented technological feature which makes the machine clean so quietly that you can even place it in your room!

Improved Sifting Screen

Litter-Robot 4 has a new and improved sifting screen which releases lesser dust particles into the air while cleaning. If you or your family member has an allergy to dust, it’s best to pick LR4.

Smaller Design

If you’re in an apartment or want a machine that takes up lesser space, go for the LR4. It’s certainly more compact at just 22″ W x 27″ D x 29.5″ H compared to LR3’s 24.5″ W x 27″ D x 29.5″ H. With LR4, you also get to choose whether you want a step or a handle. Obviously, the handle would take up lesser space than the model with the step. The step protrudes more.


If you have the LR3, you might have disliked the positioning of the nightlight under the bonnet. With the new and improved LR4, the nightlight is now at the entrance and it brightens up the litter bed area.

App Differences

As you know, there are newly upgraded, and improved smart sensors in Litter-Robot 4, such as the smart weight sensor in the curtain sensor. These sensors are reflected in the Whisker app, which you won’t see in the app of the Litter-Robot 3 Connect.

Live Monitoring of Waste Drawer

LR4 alerts you when the waste drawer is full, so you’ll always be able to know in real-time the amount of waste and when you need to empty it. There is a special motion sensor that’s positioned at the entrance, which lights up the bed area. The sensors are able to sense when the waste drops down into the waste drawer and the smart weight sensor, which is at the bottom of the machine, can also sense the weight. Essentially, both these sensors complement each other and are able to work out an accurate waste level in the drawer. They then send the data to the Whisker app to notify you. On the app’s homepage, look out for the waste drawer image, which will tell you in real-time the waste drawer levels.

In comparison, the LR 3 Connect does not tell you the waste levels in real-time. While it does tell you the amount of waste, it doesn’t update in real time. You also need to click on reset gauge on the app each time you empty out the drawer. It also calculates the waste level in a different manner from the Litter-Robot 4. With the LR 3 Connect, it calculates according to the number of rotations.

Live Tracking of Litter Level

whisker app displays my cat's weight after she used litter robot 4

Another smart feature of the Litter-Robot 4 that’s missing in Litter-Robot 3 is how it lets you know how much cat litter is in the machine. The app will tell you if it’s low or optimal. When the bar is blue, it means the cat litter level is optimal. When the bar is red in color, it means the cat litter level is low. Recording your cat’s weight is yet another special feature that LR4 offers.

The app tells you the last weight that was recorded inside the globe, according to the smart scale sensor that’s installed at the unit base. This is especially useful if you have a few cats at home and want to know which cat it was that used the little box while you weren’t watching. In contrast, the Litter Robot 3 Connect does not have a cat weight feature.

Customizing the Night Light

The LR3 Connect has a nightlight to help your cat look around at night when it’s dark. But the key difference here is the location or the positioning of the light as well as the flexibility that Litter-Robot 4 gives.

With Litter-Robot 4, you are able to switch on the night light, turn off the night light, or leave it in auto mode, meaning the night light will turn on automatically if it’s dark. You can even change the light settings to low medium or high.

With LR3 Connect, you don’t get so much customization. The only thing you can do is turn the night light off or set it to auto; you can’t change the light settings.

Sleep Mode

LR4 lets you put the machine on standby for however many hours you prefer. One example is if you need it to not operate in the middle of the night when everybody at home is asleep. You can even have different settings for weekdays and weekends. Conversely, the Litter Robot 3 Connect only lets you set the sleep mode, and it only lets you turn on the sleep mode for eight hours. Furthermore, it’s limited to a weekly setting; you can’t have different settings on weekdays and weekends.

Odor Control

Odor control is another feature that makes automatic litter boxes so popular. With normal litter boxes, you have to do regular cleanings in order to keep your home from filling with the odors that your cat leaves after they relieve themselves. This can make your home quite unpleasant. The odor control with the Litter-Robot 4 helps to prevent these odors from taking over your home.

The Litter-Robot 4 has a filter compartment that is located at the outer bottom of its Globe. This compartment has a strategic location. You are able to place a carbon filter above the waste drawer, and this traps the odors from the waste drawer as it rises. While the Litter-Robot 3 has a carbon filter, the filter is placed in front of the waste drawer near the vents. While this does help reduce odors, you will still smell them when you clean the waste drawer.

Safety Features

The safety features of both the Litter-Robot 4 and Litter-Robot 3 are designed to make the automatic litter box safer for your cat to use. The Litter-Robot 4 includes many more safety features than the Litter-Robot 3, which makes it better if you have multiple cats.

The SafeCat system is used by the Litter-Robot 4. This system consists of 3 sensors that are located at the entry of the Globe. This allows the system to detect your cat’s body entering and exiting the litter box, so it knows when to activate since you do not want the cleaning cycle to activate while your cat is still inside.

The Litter-Robot 4 also includes a SmartScale. This records your cat’s weight every time after they use the litter box. This can be useful in determining which cat was last to use the litter box, which cat uses the litter box most often, and keeping track of your cat’s weight to determine if something could be wrong with your cat.

You are also able to choose the delay time for the cleaning cycle of the Litter-Robot 4. Unlike the Litter-Robot 3, which only had options for a delay time of 3, 7, or 15 minutes, the Litter-Robot 4 offers options for delay times of 3, 5, 7, 15, or 30 minutes.

Similarities Between Litter Robot 3 and Litter Robot 4

When deciding between which automatic litter box to purchase, you want to primarily focus on what is different between the two to make the best decision for you and your cats. However, it’s also important to note the similarities.

The biggest similarity between both is that both are designed to be self-cleaning, automatic litter boxes. Both are designed to clean the litter your cat uses to allow you to not need to frequently clean the litter box after your cat does their business.

Some other features that are present in both the Litter-Robot 3 and the Litter-Robot 4 are that they both weigh approximately 24 pounds without the litter, both have wifi connectivity, both are compatible with both iOS and Andriod, and both have a litter bed that is 24×24 in size.

Litter-Robot 4 At A Glance


The new LR4 is the latest version of the popular automatic self-cleaning litter box. It features a larger capacity than the previous model, as well as an improved self-cleaning cycle that helps to keep the litter box clean and odor-free. It also includes a built-in night light and an improved waste drawer that makes it easier to empty and clean. Overall, it is a great option for those who are looking for an easy-to-use, effective, and affordable self-cleaning litter box.

Litter Robot 3 At A Glance

This is the third generation of the world’s first self-cleaning litter box. It has a durable construction made from an ABS plastic and aluminum.

There are several features of the Litter-Robot 3 that make it a great choice for your cat’s litter needs. One feature is the self-cleaning cycle. This means that the Litter Robot 3 will automatically clean itself after each use, so you don’t have to worry about scooping or changing the litter yourself. Another feature is the adjustable timer. You can set the timer to clean the litter box every 1, 2, or 3 hours, or you can set it to clean on a schedule that works for you. Lastly, the LR3 comes with a detachable bag system that makes it easy to empty and clean.

Final Verdict

The Litter-Robot 4 and the Litter-Robot 3 are both excellent automatic cat litter boxes. They are very similar in terms of features and price. The Litter-Robot 4 is the better choice for people who want an automated litter box that requires minimal maintenance. It is also a good choice for people who have multiple cats, as it can handle up to three times as much waste as the Litter-Robot 3. It’s also much quieter, so if that matters to you, go for the Litter-Robot 4. If you like having a lot more features on your mobile app, Litter-Robot 4 will be best too.

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