
I got the Litter-Robot 3 Open Air in 2016 and later on, I upgraded it into a Litter-Robot 3 Connect by installing the Connect WiFi kit in the unit so I could manage it with my phone. This device has been the best invention ever made to take care of the cat’s waste. Now I have the new Litter-Robot 4, which my cat has been using so I decided to make a comparison between both Robots. For this purpose, I created a side-by-side comparison table where you can see differences at a glance. Also, I further explain the differences in functionality and benefits. I will be updating this comparison as more features and pros & cons come up.
Rating (customers)
Dimensions (assembled)
Footprint
Entryway dimensions
Entry type
Weight (without cat litter)
Cycle delay
Dust-reducing sifting screen
Safety mechanism
How activates the unit
Types of sensors
WhisperQuiet™ Cleaning cycle
Cat suitability
Cat weight
Full drawer Indicator
Cat litter Indicator
Real-time tracking litter & drawer levels
Optional designs
Control panel location
Filter location
Sleep mode
Nightlight
Cat weight detection
Option without Wi-Fi


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
24 lbs
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


24.5” W x 27" D x 29.5" H
24.5” W x 27” D
10.25” W x 15.5” H
Oval upward-angled
24 lbs
3, 7, and 15 minutes
Weight sensor on step + inside Globe
Weight sensor on step + inside Globe
Weight sensor
Ideally up to 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
*Dimension considered for Litter-Robot 4 with step. There is another version with a handle (no step) with a 23” depth.
Differences In Core Features
These are the upgrades that are related to the operation of the litter box, which is self-cleaning, and also to the structure of the unit.
QuietSift™ operation
A special QuietSift™ patented technology allows the new Litter-Robot 4 to be a much quieter unit during a cleaning cycle. You can easily put this device next to a bedroom and you won’t notice a cleaning cycle.
Upgraded Sifting screen
The new sifting screen of the LR4 has been designed in a way that produces fewer particles in the air when it’s sifting the cat litter. This creates less dust on the surface of the rubber bottom as well. This is good for people or cats with a tendency for allergies.
Cycle Activation: Now with Two Sensors
The Litter-Robot 4 features two sensors; a Curtain Type Sensor, consisting of 3 motion “eyes” located at the entry of the Globe. This sensor detects the cat entering the litter box and activates the unit for a cleaning cycle. The other sensor is a Smart Weight-Scale Type Sensor at the bottom of the unit, called SmartScale™ technology. This Smart sensor registers the presence of a cat inside, it records the weight of the cat and also activates the Litter-Robot 4 when weight is sensed inside. We could say that both types of sensors complement each other and ensure the activation of the device, safely. The Litter-Robot 3 on the other hand, features a weight scale sensor at the bottom of the Globe that only activates when a cat steps on the step or when the feline is inside the unit. Regarding the sensors with both Litter Robots 3 and 4, you must reset the unit every time you add new cat litter or when you empty the waste drawer to refine the accuracy of the cat’s detection.
Nightlight location
The location of the nightlight in the Litter-Robot 4 is safer and more effective because it’s located at the entry, with the lights pointing directly to the litter bed. With the Litter-Robot 3 Connect, the night light was located on the underside of the Bonnet. Since the Bonnet needs to be removed periodically to clean the Globe, this small electronic piece could get damaged if not careful.
Design
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.

Also, the new LR4 offers two models: the LR4 with step and the LR4 with handle. The model with the handle is for cats that jump into the unit and don’t use the step. The model with a handle uses less space because it has a shorter depth so it’s a good option for people who has less space to accommodate the device.

Differences App Features
The addition of smart sensors to the Litter-Robot 4, such as the curtain sensor and the smart weight sensor, is reflected in new features of the Whisker App in comparison with the Litter-Robot 3 Connect.
Comparison of Whisker App Features Between LR4 and LR3
Real-time Tracking of waste drawer
The Litter-Robot 4 allows you to know in real-time how full is the waste drawer. The special motion sensor located at the entry emits 3 cone-shaped lights toward the litter bed. When the globe is rotating and the opening where the waste drops through is positioned at the bottom, these sensors detect the waste dropping and down into the waste drawer to determine the cat waste. Additionally, a smart weight sensor (SmartScale™ technology) located at the base of the unit registers the weight of the waste drawer as it increases its level. Both sensors work together for a more accurate waste level that, through the Omnisense™ detection technology, sends the information to the Whisker App. The waste drawer indicator can be seen at a glance on the App’s homepage (see figure).

The Litter-Robot 3 Connect, even though it shows the waste level indicator on the App home, is not in real-time; you need to reset the “Gauge” on your App every time you empty the drawer. The waste level indicator of the “gauge” it’s calculated based on the number of rotations, unlike the Robot 4 whose weight sensor and the Omnisense™ technology send the information to the App right after you empty the litter box and press the reset button of the unit.

Real-time tracking of litter level
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 a bar you can see at a glance in the App’s status. When the cat litter level is optimal, the bar shows blue, and when the level is low, the bar is red. I must mention that after adding cat litter, a new litter level is reflected after a cleaning cycle.

Cat weight recording
This is a unique feature of the Litter-Robot 4. The Smart scale sensor located at the bottom of the unit weighs and records the last weight detected inside the Globe and sends this information to the App. This is excellent to determine which cat used the litter box the last. This weight recording is reflected on the Litter Robot’s activity list that you can see on the Status menu. The Litter-Robot 3 Connect doesn’t feature the cat’s weight recording.

Is there any weight limit with the Litter Robot 4?
There is no weight limit for any of the Litter Robot devices and that includes the Litter Robot 4. If a cat fits inside the Litter Robot and it’s able to maneuver, it doesn’t matter how much the cat weighs, the Litter Robot will work.
Nightlight customization
The Litter-Robot 4 and Litter-Robot 3 Connect both feature nightlights to orientate cats at night. The difference is the location of the light in the globe as we mentioned previously, and also the flexibility that the LR4 offers on the Whisker App which the Connect doesn’t. The Litter-Robot 4 allows you to turn the nightlight ON (at all times), OFF (not nightlight at all), or in AUTO mode, which means the nightlight turns on automatically when it gets dark. Also, the light settings can be set to Low, Medium, or High. With the Litter-Robot 3 Connect you can only change the nightlight to OFF or AUTO mode, and you can’t set the light intensity.

Sleep Mode customization
The Litter-Robot 4 allows you to set the unit on standby for as many hours as you need. For example, if you need the litter box to stop operating from 10 pm to 8 am you can do that. Also, you can set the sleep mode on weekdays or weekends, or both. The settings for weekdays can be different from weekends as well. On the other hand, the Litter-Robot 3 Connect only allows you to set the sleep mode for 8 hours from the time you set the start. And this will repeat every day, from Monday to Monday.
My Video Comparison Between Litter-Robot 4 vs Litter-Robot 3
Get your Litter-Robot 4 and get $25 OFF! Click the link below to access this promotion. Also if you can’t afford this great self-scooping machine, there’s a payment plan. Just click Affirm at the checkout and you still will get the $25 OFF!
Odor Management Differences
The Litter-Robot 4 added some improvements for better odor control.
Carbon filter
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 raises. 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.
OdorTrap
The OdorTrap Pack is a Whisker product created for Litter Robots in order to manage odors more effectively. With the new Litter-Robot 4, you can place the OdorTrap bag inside the compartment located on the outer bottom of the Globe without the need of purchasing the holder (OdorPack Pod). With the Litter-Robot 3 in order to use the OdorTrap, you have to purchase the OdorPack Pod so you can place the bag inside the holder which is attached to the inner wall of the waste drawer by integrated magnets.


Waste Drawer
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.
Multi-cat Design & Safety Differences
Differences that may tip the balance towards the Litter-Robot 4 if you have multiple cats.
SafeCat™
The Litter-Robot 4 features the SafeCat™ system which consists of 3 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. The Litter-Robot 3 features a weight sensor on the 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.
SmartScale™
The Litter-Robot 4 features a smart scale-type sensor that records the cat’s weight right after every use. This way you can recognize which cat used the litter box the last by their weight.
Entryway
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 LR3 Connect features a narrower entry with an oval shape.
Cycle Delay
The delay time is the time between the Litter-Robot getting activated and the actual cleaning cycle. With the Litter-Robot 3 Connect the settings are 3, 7, and 15 minutes. With the Litter-Robot 4, you can decide if the cycle delay is 3, 5, 7, 15, or 30 minutes. The 30-minute wait time is good for multi-cat use, this way two cats could use the litter box before a cleaning cycle.
Final Thoughts
I have been using the Litter-Robot 3 for six years and I can attest that it’s the best invention created for cat owners. Now I have been using the Litter-Robot 4 for almost nine months and I can see improvements regarding the Connect, but both units accomplish greatly the main function which is self-cleaning the litter box efficiently. Personally, the main difference in features: the sensors, litter level indicator, and noise level, are great improvements. Though in my case they not are essential and I could live without them because my Robot is in the laundry room away from the living areas, and I empty the waste drawer every Sunday together with pouring more cat litter inside the Globe. But I am sure so many cat owners appreciate the higher safety level of the new Litter-Robot 4, the lower noise level, the litter indicator, the cat weight recording, the smaller footprint, the roomier interior, and so much more.
In Conclusion
Both, the Litter-Robot 4 and the Litter-Robot 3 are excellent devices! I suggest getting the Litter-Robot 4 if you are a multiple cat owner who needs a quieter device when operating, and if you need a reminder to refill the globe with cat litter. Also, the new Litter-Robot 4 is suitable for cat owners that want to manage more options and flexibility with some features on the Whisker App.
Get your Litter-Robot 4 by visiting the link below and unlock $25 off your purchase! (the $25 off will be reflected at the checkout) You can choose a payment plan by selecting Affirm at the checkout.
couldn’t get the 25.00 discount to work?
Hi Denise, the $25 off shows at the checkout.
Does the waste drawer of the 4 hold the same amount of waste as the 3? I was hoping for a little more room.
Hi Sondra, according to my experience, I find the waste drawer of the LR4 to be roomier than the Connect. The reason is that when I had to open the waste drawer with the Connect, after a week, the waste drawer looked usually almost full (65%). Now when I open the waste drawer of the Litter Robot 4 the waste looks much smaller inside the drawer after a week of use (about 45%).
Hi Lorena,
wow! This is a really, really good report and comparison! Thanks a lot for that! You really put a lot of effort into it. I’m excited! And now I’m even more looking forward to the market launch of the LR4 in Europe (I live in Germany), which unfortunately won’t be before the beginning of 2023. But then – I’m sure – me and my 3 cats will be very happy about it. :o)
Kind regards, Claudia
Hi Claudia, I am sure you and your cats will love it. I am very happy to help cat owners with my review. Thanks so much for your motivating comment.
This was so helpful!
Thank you!
Great video.
I’ve had my LR3 for 3 years and love it. I will likely add an LR4.
Years ago I had one of the first models. I had 2 cats and terrible back pain that made cleaning litter difficult. It really made life better for me. The LR3 was a huge improvement and the LR4 looks even better.
Hi Michelle, thanks for your comment and I agree with you. I am also a big fan of the Litter Robots. I love both, the Connect and the LR4, but the fact that the LR4 is quieter is much better. Don’t forget to get $25 off your purchase by using my link. Good luck and thanks for sharing your experience!
Hi Lorena,
Awesome review! I’ve had my LR3 for almost 3 yrs, and am starting to have some issues. I travel and sometimes up to a week. The last two times I traveled I had issues and came home to unpleasant surprises. The 1st problem was a pinch detector and the globe was upside down. Poor Kitty had no place to go. And this last time it went offline and I had no way to turn it off and on to get it back on. Kitty wouldn’t go in it because it was was dirty. But my question for the LR4 is, Kitty is a high sprayer, and pees more toward the opening and front of the box. Do you think the LR4 would work for a front high sprayer Kitty or should I stick with the LR3. I sure do like the bigger waste drawer and the ease of changing the litter bag.
Thank you for your input,
Delynn
Hello Delynn, I have read some complaints about the Litter Robot Connect pinch on YouTube, but I have never had that issue (mine is from 2016 as a reference) and I believe the current Litter Robot Connect units don’t have that pinch piece either. I recommend you when you leave for days place a regular cat litter box just in case. To place a backup option is recommended with any type of automatic device such as feeders, fountains, etc. Regarding a high sprayer cat that points in any direction when doing his business, I would suggest sticking with the Connect in that case since the entry of the Litter Robot 4 is wider with a round flat-faced entry. Hope that helps!
Thank you Lorena. I was thinking the same thing about the opening of the LR3, but I so want the new one ..LOL!! I will stick with the one I have. Thanks Again :-)
You are welcome, Delynn :)
Is there a weight limit? I’m adding a main coon to the family. They can get up to 25+ pounds.
Hello Mia, I don’t believe there is a weight limit as long as a domestic cat is using the Litter Robot.
My cat tends to high pee on the back of his current box. Usually resulting in leaks out the back! How easy is it to clean the back of either model?
Hi Sandy, you can see how to wash the globe in the bathtub here https://youtu.be/GmLFIYIjFHM or with a hose outdoors here https://youtu.be/yFL7Y30ruto
Hi, awesome and helpful review. I was wondering how often do you need to hand clean the inside unit and which one is easier to clean.
Hi Diana, in my case, I have one cat and she is not messy and doesn’t pee high like male cats so I clean the Globe every month, especially now that I use a good cat litter that doesn’t let clumps stick into the globe. To me, the LR4 has been easier to clean.
Love these reviews. Could you please tell me if the LR4 seems it’ll fit a large cat better than the LR3 does? My big guy doesn’t fit in the LR3 so I still have a traditional box which I’d love to do away with completely. Thank you!
Hi Melissa, how cats accommodate will depend on their versatility. Large cats can do their business with no issues since they can stick part of their heads out the globe while doing their business. Cats can adapt very well to the Litter Robot, there are multiple testimonies.
Hi, We have been using the LR3 for about 5 years and it is starting to halt mid cleaning cycle. Does the LR4 connect have a wi-fi reset function so that we can remotely reset the dumping function. We are afraid to leave the LR for a day or so because of that problem. ( We deep clean the system often.)
Thank you.
Hi Lauren, yes, you can remotely cycle and reset the LR4 from the Whisker app.