Litter & Litter Tech
Litter-Robot 4 vs Leo's Loo Too
Two enclosed self-cleaners at the top of the category. Each publishes the specification the other leaves blank, and that decides more than any feature list.
Affiliate disclosure: we earn a commission if you buy through our links, at no extra cost to you. It never changes which product we rank first — here is how we're funded.
Everyone in this category says they tested twenty litter boxes. We have not tested any, and we say so. What we do instead: compile the published specs, read the manuals, and do the arithmetic on what this gear costs to run and how it behaves once there is more than one cat using it. Every spec is linked to the document it came from. Prices are checked daily — last verified September 29, 2026. Here is exactly how we pick.
These two are the closest rivals in the enclosed self-cleaning category, and the most useful way to separate them is not features. It is which numbers each company is willing to print.
What each one publishes
| Specification | Whisker Litter-Robot 4 | Casa Leo Leo's Loo Too |
|---|---|---|
| Entryway | 15.75" x 15.75" | Not published |
| Footprint / height | 22" W x 27" D x 29.5" H | 22" x 24" x 27.6" |
| Weight, empty | 24 lb | 27.5 lb |
| Cat weight | 3-25 lb | Up to 20 lb (Casa Leo); 1-20 lb typical, 55 lb maximum load (retailer) |
| Litter capacity | Not published | 1.5 gal (6 L) |
| Waste drawer capacity | Not published | 1.5 gal (6 L) |
| Power | 15 V DC, 400-1000 mA (6-15 W) | Not published |
| Noise | Not published | About 30 dB |
| Weight sensing | Not published | Four sensors, accurate to plus or minus 1 lb |
| Warranty | 1 year; 3-year plan optional | 1 year; 3-year extension available |
Manufacturers' and retailers' published figures. Blank cells are blanks in the makers' own specifications, not gaps in our research.
Read that table as two halves. Whisker publishes the two numbers that decide whether the machine suits your cat and what it costs to leave switched on. Casa Leo publishes the two that decide how often you empty it and whether you will hear it at night. Neither company publishes the other’s.
The cat decides this first
Whisker publishes a cat weight range of 3 to 25 lb and an entryway of 15.75 by 15.75 inches — about 248 square inches of opening.
Casa Leo publishes cats up to 20 lb and no entryway dimension at all. The retailer listing adds a 1 to 20 lb typical range with a 55 lb maximum load on the sensors.
So a Maine Coon or a large domestic shorthair near the 20 lb mark is not a close call: one maker has already placed that cat outside its range, and the other publishes an opening you can measure your cat against. Our large-cat page ranks the whole category on exactly this.
Floor space, worked
Litter-Robot 4: 22 x 27 inches = 594 square inches, standing 29.5 inches tall.
Leo’s Loo Too: 22 x 24 inches = 528 square inches, standing 27.6 inches tall.
That is about 11 percent less floor and 1.9 inches less height — the same width, three inches shallower. If the box has to live under a shelf or beside a toilet, measure the depth before anything else. Our small-space page uses the same usable-floor-per-square-foot approach across the category.
What you can cost out, and what you cannot
This site computes running costs from published power figures. Here, only one of the two makes that possible.
Whisker publishes a 15 V DC, 400-1000 mA supply — a 6 to 15 W range.
At the ceiling: 15 W is 0.015 kW x 8,760 hours = 131.4 kWh a year.
At the EIA average residential rate of 18.34 cents per kWh, that is about $24.10 a year, and realistically less, because a self-cleaning box does not draw its ceiling around the clock.
For Leo’s Loo Too, Casa Leo publishes no wattage. There is no arithmetic to show, so we are not going to invent a comparison figure — and a blank here is worth noticing in a category sold partly on convenience.
Neither machine has the consumable problem that decides some of these comparisons: both run on ordinary clumping litter, so there is no proprietary tray subscription to cost in. That is the axis that separates the Litter-Robot from the ScoopFree in our other head-to-head, and it simply does not apply here.
Capacity, and how often you touch it
Casa Leo lists 1.5 gallons of litter and a 1.5 gallon waste drawer — a one-to-one ratio, which is a reasonable design for a single-cat household and gets tight quickly with two or three cats sharing one unit.
Whisker publishes neither figure for the Litter-Robot 4. Its drawer is widely described as large, and we have no published number to put against that description, so the honest position is that drawer intervals cannot be compared on paper. Whichever you buy, our cleaning guide makes the point that matters more: every published capacity figure is a single-cat figure, and it halves with each extra cat sharing the machine.
Odor and noise
Casa Leo publishes a UV-C light in the waste drawer alongside a sealed drawer and a carbon filter, and about 30 dB of operating noise. Whisker publishes no decibel figure for the Litter-Robot 4, which means the quieter machine on paper is the one that printed a number — not necessarily the quieter machine in your bathroom.
The gear discussed here
The Litter-Robot 4 is the one to buy if your household includes a large cat, or if you want to know what the thing costs to run before you plug it in. The 15.75 inch square entryway is the largest published opening in our data, the 3 to 25 lb range covers nearly every domestic cat, and the 6 to 15 W supply is the only figure in this comparison that converts into money. The honest cons: Whisker publishes neither capacity nor noise, it is the larger machine on the floor by about 11 percent, and the standard warranty is one year unless you pay for the three-year plan.
Leo’s Loo Too is the one to buy if space or noise is the binding constraint, and it is the better-documented machine in the ways that affect daily use: 1.5 gallons of litter, a 1.5 gallon waste drawer, about 30 dB, four weight sensors accurate to a pound, and UV-C in a sealed drawer. It is also about three inches shallower and nearly two inches shorter. The honest cons: Casa Leo publishes no entryway dimension and no wattage, its published ceiling is 20 lb rather than 25, and at 27.5 lb empty it is the heavier unit to move for cleaning.
How to decide in one minute
- Weigh the cat. Near or above 20 lb, buy the Litter-Robot 4 — Casa Leo has published its own limit.
- Measure the space, depth first. If you are within three inches, Leo’s Loo Too is the one that fits.
- Count the cats. Two or three sharing one machine makes the published 1.5 gallon drawer a daily job rather than a weekly one.
- Decide whether the bedroom wall matters. Only one of these publishes a noise figure at all.
- Check the entryway against your cat, not against the marketing. A cat that dislikes enclosed boxes is a reason to look at our open-top comparison instead.
Compare the two
There is no universal winner here, which is why the table above is the page. The Litter-Robot 4 is the safer buy for a big cat and the only one of the two you can budget for honestly. Leo’s Loo Too is the better fit for a small room and the more transparent machine about the things you deal with every week. If neither feels justifiable yet, our worth-it page makes the case against both, and our automatic litter box roundup covers the rest of the category.
- Big cat, or you want a costable machine: Litter-Robot 4.
- Tight floor space, or noise matters: Leo’s Loo Too.
- Cat that refuses enclosed boxes: neither — look at an open-top unit.
The gear discussed here
Specs are the manufacturer's own, linked to the page they came from. Prices come from a live daily check; where we have no verified price we say so rather than print a stale one.
Whisker Litter-Robot 4
Whisker · Automatic litter box · Our score 8.1/10
Reference link This one sells direct and we earn nothing on it. We link it anyway because it belongs in the comparison. How we're funded.
The biggest entryway and the largest published cat-weight range of the enclosed units, and the only one whose maker publishes an actual power-supply spec you can cost out.
Published specs
| Entryway | 15.75" x 15.75" |
|---|---|
| Footprint / height | 22" W x 27" D x 29.5" H |
| Weight, empty | 24 lb |
| Cat weight range | 3-25 lb |
| Power supply | 15 V DC, 400-1000 mA (6-15 W) |
| Warranty | 1 year, 3-year plan optional |
| Globe / drawer capacity | Not published by Whisker |
Source: Whisker -- Litter-Robot 4 product page and power supply spec article
Whisker's own spec sheet accepts a 15 V supply between 0.4 A and 1.0 A. Take the 1.0 A ceiling: 15 W x 24 h x 365 = 131.4 kWh, x $0.1834 = $24.10. That assumes the motor runs flat out every hour of the year, which it does not -- so the real figure is well below this. The consumables are the actual cost.
What the specs favor
- Largest published entryway of the enclosed units here, at 15.75 inches square
- Whisker publishes a real power-supply rating, so running cost is computable
- Cat weight range published as 3-25 lb
- Three-year extended warranty available at purchase
What they don't
- Whisker does not publish globe or waste-drawer capacity, which is the number that actually decides how often you empty it with three cats
- Waste drawer liners are a proprietary consumable at $25 per 25-pack
- Carbon filter is a separate monthly consumable
- Sells mainly direct, so there is no reliable Amazon price to track
You have five cats. Whisker rates the newer Litter-Robot 5 for up to five and this one carries no published cat-count rating at all -- buying the older unit for a bigger household is guessing.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Casa Leo Leo's Loo Too
Casa Leo · Automatic litter box · Our score 7.9/10
#ad Price as of September 29, 2026. Prices move; we check daily. How we're funded.
Publishes both litter and waste capacity at 1.5 gallons each, which is more than Whisker will tell you about either of its units.
Published specs
| Litter capacity | 1.5 gal (6 L) |
|---|---|
| Waste drawer capacity | 1.5 gal (6 L) |
| Dimensions | 22" x 24" x 27.6" |
| Weight | 27.5 lb |
| Weight sensors | Four, accurate to plus or minus 1 lb |
| Cat weight | 1-20 lb typical; 55 lb maximum load |
| Odor control | Bamboo carbon filter plus UV |
Source: Chewy -- Casa Leo Leo's Loo Too listing and specification block
Published 6 L litter capacity. At the 2-inch depth the Ohio State Indoor Pet Initiative recommends, that is a full charge of litter every time you strip it -- roughly a 12 lb bag of clumping clay every two changes on package volumes.
What the specs favor
- Publishes litter AND waste capacity, both 1.5 gallons
- Four weight sensors with a published accuracy of plus or minus 1 lb
- Bamboo carbon filter is a standard consumable, not a proprietary tray
- Takes ordinary clumping litter
What they don't
- 27.6 inches tall and 27.5 lb -- awkward in a small bathroom
- Published cat range tops out around 20 lb for comfortable use
- 6 L waste drawer is smaller than the Neakasa M1's 11.23 L
You have a Maine Coon or a Ragdoll over 20 lb. The published comfortable range stops around 20 lb and a large cat in a rotating drum is not a place to find out where the limit is.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Common questions
Which is better for a big cat, the Litter-Robot 4 or Leo's Loo Too?
Which one is cheaper to run?
Does either maker publish litter and waste capacity?
Which is quieter?
Which takes up less room?
Sources
- Whisker -- Litter-Robot 4 product page and power supply spec article
- Chewy -- Casa Leo Leo's Loo Too listing and specification block
- Casa Leo -- Leo's Loo Too product page (cats up to 20 lb / 9 kg, about 30 dB, UV-C light and sealed waste drawer, 1-year warranty with a 3-year extension available)
- U.S. Energy Information Administration -- average residential electricity price, 18.34 cents per kWh
Read next
- Best Automatic Litter Boxes (2026)
The head-term roundup, ranked on published capacity and consumable model rather than app features.
- Litter-Robot 4 vs Neakasa M1
The enclosed globe against the open top, on published footprint, weight range, waste capacity and noise -- with a verdict by household.
- What an Automatic Litter Box Actually Costs to Run
The full year-one and year-two running cost of every major automatic litter box, computed from published prices with the arithmetic shown.
- Are Automatic Litter Boxes Worth It?
Break-even arithmetic against ordinary boxes, worked from published prices, with a clear answer for one, two and three cat households.
- Best Automatic Litter Boxes for Large Cats (2026)
Automatic boxes filtered on published weight range and entryway size for Maine Coons, Ragdolls and other large breeds.