My cat used the Litter-Robot 3 for six years and I switched to the Litter-Robot 4 in 2022. The Robot 3 was still functioning but I was invited to be a Beta tester for the Robot 4 and that’s why I switched. Using my experience with both units I created a full comparison of the Litter Robot 3 vs Litter Robot 4. As I continue to discover more features and differences, I’ll be updating this comparison regularly. But before going into details the first question is why did Whisker create the Litter-Robot 4 while keeping the Litter-Robot 3?
Why did Whisker create the Litter-Robot 4?
The Litter-Robot 4 was created as an answer to customers’ feedback, adding more features to this great automatic litter box. Whisker’s mission is to make the cat owners’ lives easier. They feature the Litter-Robot 4 as a multi-cat device because some changes satisfy the needs of multi-cat owners. The Litter-Robot 3 Connect, on the other hand, is a great option with a lower price for cat owners who may not need some of the features offered in the upgrade. This way everyone’s happy.
In this comparison of Robot 4 vs Robot 3, you will see
- A side-by-side comparison table
- The difference in core features of Litter-Robot 4 vs Litter-Robot 3
- The difference in settings on the Whisker App
- Odor control between the Robot 4 vs Robot 3
- Safety & multi-cat benefits of the Litter-Robot 4 vs Litter-Robot 3
- Difference in price and why
- My thoughts as a long-term user of both
- Which one is better according to my experience
Weight (without cat litter)
Dust-reducing sifting screen
How activates the unit
Types of sensors
WhisperQuiet™ Cleaning cycle
Full drawer Indicator
Cat litter Indicator
Real-time tracking litter & drawer levels
Control panel location
Cat weight detection
Option without Wi-Fi
Maximum weight on globe
22” W x 27" D x 29.5" H *
22” W x 27” D
15.75” W x 15.75” H
Wide round flat faced
3, 5, 7, 15, and 30 minutes
Motion sensor at the entry
Motion sensor at the entry + on step + inside Globe
Curtain sensor & SmartScale™ sensor
Suitable for up to 4 cats
Adult cats and kittens weighing 3+ lbs
Handle and Step
On top of the Globe
Outer bottom of Globe
Custome schedule | Weekdays/Weekends
Auto, ON or OFF | High, Medium or Low
No cat weight limit
24.5” W x 27" D x 29.5" H
24.5” W x 27” D
10.25” W x 15.5” H
3, 7, and 15 minutes
Weight sensor on step + inside Globe
Weight sensor on step + inside Globe
Ideally up to 2-3 cats
Adult cats and kittens weighing 5+ lbs
At the bottom, on the right side
On waste drawer's vents
8 hours from start time
Auto / OFF
No cat weight limit (size limitations)
*Dimension considered for Litter-Robot 4 with step. There is another version with a handle (no step) with a 23” depth. **Open Air has been discontinued.
Differences in core features: Litter Robot 3 vs Litter-Robot 4
These upgrades are about the operation and design of the two Litter-Robots.
The noise level when rotating: Litter-Robot 4 is quieter
The new Litter-Robot 4 is way quieter than the Litter-Robot 3, all thanks to its fancy QuietSift™ patented tech. Basically, it’s so quiet you can stick it near your bedroom and not even notice it cleaning – it’s like a mosquito buzz in the next room, super low-key. I recorded both units while rotating with a meter distance in front of the device. Listen to these audios with about 40% volume on your device for a more accurate sound level.
Litter-Robot 3 Rotation Noise Level:
Litter-Robot 4 Rotation Noise Level:
A little less dust: Upgraded sifting screen of the Litter-Robot 4
When the Litter Robot is in action, it does produce some dust, but it’s mainly contained within the globe while it sifts. The redesigned sifting screen in the Litter-Robot 4 helps minimize dust during cleaning, reducing airborne particles that settle on the rubber base. This feature is particularly helpful for people or cats with allergies. Choosing a suitable cat litter for the Litter Robot is also crucial in this regard.
Litter-Robot 4 has two sensors while Litter-Robot 3 has one sensor
The Litter-Robot 4 boasts two types of sensors for enhanced functionality: an infrared sensor at the entrance with three “eyes” that detects the cat’s entry and sets a cleaning delay, and a SmartScale™ sensor at the base, which not only registers the cat’s weight but also activates the unit when weight is detected. These sensors work together to ensure safe operation. In contrast, the Litter-Robot 3 only features a single weight scale sensor at the base, activating when the cat uses the step or it’s inside the globe. The additional motion sensors in the Litter-Robot 4 will ensure the activation of the unit by detecting the cat’s body, independently of the weight sensor. Regardless of the model, resetting the unit after adding new litter or emptying the waste drawer is necessary to maintain accurate cat detection.
Location of nightlight: Safer on Litter-Robot 4
The location of the nightlight electronics in the Litter-Robot 4 is safer and more effective because it’s located at the top entry, inside the Litter-Robot 4’s bezel. The nightlight of the Litter-Robot 3 Connect is located on the underside of the Bonnet, being exposed through the globe’s opening. Also, since the Bonnet needs to be removed periodically to clean the Globe, this small electronic piece could be damaged if not careful with the manipulation of the bonnet.
Location of nightlight electronics in the Litter-Robot 3 vs Litter-Robot 4
Design: Litter-Robot 4 is neater than the Litter-Robot 3
The new Litter-Robot 4 is not only more compact with a neater look but also uses less space on the floor since it features a smaller footprint. The width of the Litter-Robot 4 is 1.5 inches narrower than that of the Litter-Robot 3, and its depth is 2.5 inches less than the Robot 3, while the height is the same. With the Litter-Robot 4, you can choose between a waste drawer with a step or with a handle. The waste drawer with a handle is for cats that jump into the unit and don’t use the step. The handle uses less space because it has shorter depth so it’s a good option for people who have less space to accommodate the device.
You can choose a waste drawer with a step or with a handle with the Litter-Robot 4.
Whisker app features: Litter-Robot 4 vs Litter-Robot 3
The addition of smart sensors to the Litter-Robot 4 is reflected in new features, reports, and functions of the Whisker App in comparison with the Litter-Robot 3 Connect.
Real-time tracking of waste drawer with Litter-Robot 4
The Litter-Robot 4 offers real-time monitoring of the waste drawer’s fill level through the Whisker App. Using motion sensors positioned at the entry, three cone-shaped lights are directed toward the litter bed. As the globe rotates and the waste opening aligns at the bottom, these sensors detect waste dropping into the drawer, accurately gauging waste levels. Additionally, a smart weight sensor, utilizing SmartScale™ technology and located at the unit’s base, tracks the weight increase of the waste drawer. Both sensors collaborate to provide precise waste level information, which is seamlessly relayed to the Whisker App via Omnisense™ detection technology. Users can easily view the waste drawer indicator on the App’s homepage for convenient monitoring.
The Litter-Robot 3 Connect instead, doesn’t show the new waste drawer level in real time after you empty it. On the App, you need to “reset” to empty the gauge every time you empty the waste drawer. The waste level indicator of the gauge on the App is calculated based on the number of rotations, not through a weight sensor. With the Litter-Robot 4, as soon as you empty the waste drawer and push the reset button on the panel the new level will update automatically on the App, starting from zero.
Real-time tracking of litter level with Litter-Robot 4
The smart sensors of the Litter-Robot 4, together with the Omnisense™ technology, allow this unique feature of showing on your App how much cat litter the Robot has. It will indicate, Optimal or Low in the App’s status. When you add new cat litter you will see the new level after a cleaning cycle. With the Litter Robot 3 you don’t have this indicator.
Litter-Robot 4 registers the cat’s weight on the Whisker app
This is a unique feature of the Litter-Robot 4 that Litter-Robot 3 doesn’t have. The SmartScale TM technology of the bottom sensors weighs and records the last weight detected inside the Globe and sends this information to the Whisker App. You can see the latest registered weights on the daily activity list of the STATUS menu. You can track your cat’s weight this way. This is one of my favorite features as I can control my cat’s weight.
Pet profile on Litter-Robot 4: Monitor multiple cats’ weight & usage
With the Litter-Robot 4, you can track each cat’s weight via the Whisker App. After connecting the unit to Wi-Fi, you create a pet profile for each cat. Within these profiles, you’ll find a weekly weight chart and a list of recent weight recordings, reflecting litter box usage over the past few days. Each profile includes your cat’s photo, along with details like breed, gender, age, diet, weight, and health information. SmartScale technology automatically records and displays weight data, though it won’t function if your cats have identical weights. The Litter Robot 3 doesn’t have SmartScale technology so it doesn’t record the cats’ weight. Check out a brief video demonstrating how to use the pet profiles on the Whisker App for weight tracking.
Nightlight options: Litter-Robot 4 vs Litter-Robot 3
Both Litter Robots have a nightlight to guide cats at night. The Litter-Robot 4’s nightlight illuminates the litter bed precisely, with additional settings available on the Whisker App: ON (constant), OFF, or AUTO mode (activates in darkness). You can also adjust the light intensity (Low, Medium, High). The Litter-Robot 3 Connect offers only OFF or AUTO mode for the nightlight, without intensity adjustment. The intensity level expands the illumination within the globe.
Sleep mode schedule: More flexibility with Litter-Robot 4
Sleep Mode is a feature that allows you to set a schedule for the Litter-Robot so it doesn’t rotate during specific times, such as at night. With the Litter-Robot 4, you have the flexibility to program Sleep Mode for any duration you prefer. For example, you can set it to pause from 10 pm to 8 am. Additionally, you can customize Sleep Mode to apply only on weekdays, weekends, or both, and you can have different schedules for each group of days. In contrast, the Litter-Robot 3 Connect allows you to set Sleep Mode for a fixed 8-hour period, which repeats daily without the option for customization.
My video comparison between Litter-Robot 4 vs Litter-Robot 3
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Odor control between the Litter-Robot 3 & Litter-Robot 4
The Litter-Robot 4 added some improvements for better odor control.
Litter-Robot 4 has a more strategic location for the carbon filter
This change in the design plays a major role in better odor control for the Litter Robot 4. The Litter-Robot 4 features a filter compartment at the outer bottom of the Globe. In this compartment, you place the carbon filter that will be sitting right above the waste drawer. This location is strategic because it traps the odors from the waste drawer as it rises. The Litter-Robot 3 Connect, instead, features the carbon filter in front of the waste drawer where the vents are. This helps reduce odors, but odor gases rise and you may smell it when you open the waste drawer.
Carbon filter location on Litter-Robot 3 vs Litter-Robot 4
OdorTrap system: More options to place the pack with Litter-Robot 4
The OdorTrap Pack is a Whisker product created for Litter Robots to manage odors more effectively. With the new Litter-Robot 4, you can place the OdorTrap bag inside the filter compartment located on the outer bottom of the Globe without the need to purchase the holder (OdorPack Pod). With the Litter-Robot 3 to use the OdorTrap, you have to purchase the OdorPack Pod so you can place the pouch inside the holder which is attached to the inner wall of the waste drawer by integrated magnets.
A redesigned waste drawer of the Litter-Robot 4
The Waste Drawer of the Litter-Robot 4 is tightly sealed, containing odors much better. Also, the waste drawer is deeper, the edges don’t have clips and nooks to tuck the bag in, and instead, the edges are flat allowing you to simply wrap the bag on top. The Litter-Robot 3 waste drawer edges are not smooth and for this reason, the drawer sealing when shut is less in comparison to the Litter-Robot 4, although the litter clumps and odors are still pretty well contained.
A better-sealed unit with the Litter-Robot 4: Sealing strips
The Litter-Robot 4 incorporates four types of sealing strips, each serving a unique function. Bezel sealing strips around the upper waste port prevent litter or odors from escaping during operation by creating a secure seal between the globe and the base. Lower globe sealing strips maintain a tight seal between the waste drawer and the globe, while lower waste port sealing strips minimize litter or odors from escaping the waste drawer opening. Additionally, upper waste port sealing strips ensure a secure seal when waste is deposited into the waste drawer. On the other hand, the Litter-Robot 3 features sealing strips on the upper waste port only. The Litter-Robot 4 addition of three extra sealing strips contributes to a cleaner and more hygienic environment within this unit.
Four types of sealing strips on the Litter-Robot 4
Sealing strips on Litter-Robot 3
Safety & multi-cat benefits: Litter-Robot 4 vs Litter-Robot 3
Differences that may tip the balance towards the Litter-Robot 4 if you have multiple cats.
SafeCat™: Litter-Robot 4 adds infrared sensors to detect the cat
The Litter-Robot 4 features the SafeCat™ system which consists of 3 infrared motion sensors at the entry of the Globe. This patented technology called Omnisense™ allows the activation of the unit by the detection of the cat’s body crossing the entry. This curtain-type sensor also ensures the cat’s safety in case the Globe is rotating and a cat enters the unit because it stops completely the operation if it senses the cat. To ensure the optimal functioning of the sensors you need to keep them clean. On the other hand, the Litter-Robot 3 features a weight sensor on the entry step and at the bottom of the unit so the rotation stops if a cat steps on the step or if it jumps into the Globe by detecting the cat’s weight inside.
Tracking of your cats’ weight
As discussed earlier regarding the App’s capabilities with the Litter-Robot 4, the Pet Profile allows you to track the individual litter box activity of each cat by reviewing SmartScale’s daily weight registrations. Additionally, you can assess each cat’s litter box usage by accessing the History menu.
Entryway: Larger cats don’t feel trapped with Litter-Robot 4
The new Litter-Robot 4 features a wider entry and roomier space inside the Globe for cats of any size. Large cats can enter the unit much easier. The Litter-Robot 3 Connect features a narrower upward entry with an oval shape that makes cats more afraid of entering the unit for the first time.
More delay-time options with the Litter-Robot 4
The “delay time” is the time between the Litter-Robot getting activated when sensing the cat’s body inside the globe and the rotation of a cleaning cycle. With the Litter-Robot 3 Connect the settings of delay time are three, 3, 7, and 15 minutes. With the Litter-Robot 4, you can choose between five delay times, 3, 5, 7, 15, and 30 minutes. A shorter delay time is useful when using a fast-clumping cat litter that could attach to the rubber if sitting too long. The 30-minute wait time is good for multi-cat use, this way two cats could use the litter box before a cleaning cycle.
Difference in Price
Litter-Robot 4 is $150 more expensive than the Litter-Robot 3 Connect. The Litter-Robot 4 costs $699 while the Litter-Robot 3 costs $549 (you can apply $50 Off in any by visiting the link at the end). The reason for this price increase relies on the fact that more advanced tech was incorporated into the newer model. This technology allows you to enjoy a quieter unit, a less dusty rotation, a smart sensor that “reads” the cat waste and litter level, and so on. The extensive Whisker R&D research is not only reflected in the patented technologies that are built into the machine but also in the development of the Whisker App that offers more features.
How was the switching to the Litter-Robot 4 for me?
My cat smoothly transitioned from the Litter-Robot 3 to the Litter-Robot 4 in 2022 after six years of use. The switch has been hassle-free overall. The new features of the Litter-Robot 4 are not crucial for me, except for the weight recording, which I find particularly useful. The quieter operation is a nice touch, although noise was never a big issue for me since I keep it in the laundry room and use sleep mode at night. Features like the waste and litter level indicators are handy, but not essential for me since I empty the drawer weekly, topping off the globe with litter in the process. However, I recognize that these upgrades might be valuable for cat owners with busier households or limited space.
Bottom line: Which is better? Litter-Robot 4 or Litter-Robot 3?
Both, the Litter-Robot 4 and Litter-Robot 3 work very well. Multi-cat owners may benefit better from the Litter-Robot 4’s lower operation, cat litter indicator, cat usage tracking, and more options with the Whisker App. Litter Robot 3 is better for 1 or 2 cats and placed away from living areas.
You will benefit better from the Litter-Robot 4 if you need the following:
1. To locate the Litter-Robot 4 in a living area or small apartment.
2. More waste capacity and odor control on multi-cat usage, with a deeper and better-sealed waste drawer.
3. To monitor the cat’s weight on the Whisker App and which cat uses the litter box more.
4. A real-time reminder on the App to refill the globe and when to empty the waste drawer.
5. Flexibility on the App features, such as nightlight settings, delay time, and sleep mode schedule.
I suggest getting the Litter-Robot 3 Connect in the following cases:
1. You have a designated room to place the Litter-Robot away from the living areas
2. If you have a routine to empty the waste drawer together with topping the litter off.
3. You don’t need more setting options on the Whisker App (nightlight, delay time, sleep mode)
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