Litter & Litter Tech
Litter-Robot 4 vs Neakasa M1
These are the two most different automatic boxes we track: one is a sealed globe a cat climbs into, the other is an open tray with a rake. The published numbers split just as cleanly.
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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 25, 2026. Here is exactly how we pick.
Most automatic litter box comparisons are between two versions of the same idea. This one is between two different ideas, and the published specifications make the choice unusually clear.
The one structural difference
The Litter-Robot 4 is a sealed globe. The cat steps through a 15.75 inch square opening into an enclosed chamber, and the globe rotates to sift waste into a drawer below. The Neakasa M1 is an open tray: no roof, no tunnel, and a rake mechanism underneath.
Everything else follows from that. The globe contains odor better and asks more of the cat; the open tray asks nothing of the cat and contains less. Our automatic box roundup covers the wider field, and our Litter-Robot 4 against 5 page covers the in-family upgrade.
What each one publishes
| Specification | Litter-Robot 4 | Neakasa M1 |
|---|---|---|
| Form | Enclosed rotating globe | Open top with a rake |
| Footprint | 22" W x 27" D | 23.26" x 20.67" |
| Height | 29.5" | 20.2" |
| Cat weight range | 3 to 25 lb | 2.2 to 33 lb |
| Entry | 15.75" x 15.75" opening | Step-in, 13.86" entry height |
| Waste capacity | Not published by Whisker | 11.23 L bin |
| Litter capacity | Not published | 7.17 L |
| Noise | Not published | Not more than 50 dB |
| Empty weight | 24 lb | 22.81 lb |
Manufacturers' published figures. Blank cells are blanks in the maker's own specification, not gaps in our research.
Floor and height
Litter-Robot 4: 22 x 27 = 594 square inches of floor, standing 29.5 inches tall.
Neakasa M1: 23.26 x 20.67 = 481 square inches, standing 20.2 inches.
The M1 uses about 19 percent less floor and is 9.3 inches shorter. In a laundry room with a counter or a shelf over the box, that height difference is often the whole decision -- a 29.5 inch globe needs clear air above it for the lid to work.
The cat that has to use it
The M1 publishes a range of 2.2 to 33 lb. The Litter-Robot 4 publishes 3 to 25 lb. That is a real gap at both ends: a small kitten below 3 lb may not be detected by the Litter-Robot, and a cat over 25 lb is outside Whisker’s own range.
There is a second, less obvious size question. An enclosed globe is a tunnel, and some cats simply will not use one -- the Ohio State Indoor Pet Initiative reports that cats generally prefer large, uncovered boxes and that covered boxes may be refused if they are not kept extremely clean. An open-topped automatic box sidesteps that objection entirely, which is why the M1 is the safer buy for a cat whose preferences you do not yet know.
What is published, and what is not
This site ranks on what makers will put in writing, and here the two are not equal. Neakasa publishes litter capacity, waste bin capacity and a noise ceiling. Whisker publishes none of those three for the Litter-Robot 4 -- our running costs page notes the drawer capacity gap, which is the figure you would want in order to predict how often you empty it.
- Waste bin at three cats: the M1’s 11.23 L works out at about four days. There is no equivalent Litter-Robot figure to set beside it.
- Noise: 50 dB against a blank.
- Electricity: the Litter-Robot 4 does publish a 6 to 15 W supply, which is how we compute its $24.10 a year worst case. The M1 does not publish wattage.
So each maker leaves a different hole. Neakasa is more forthcoming about capacity and noise; Whisker is more forthcoming about power.
The verdict by household
- A large cat, or a cat under 3 lb: the M1, on its published weight range.
- A small room, or a shelf above the box: the M1, on footprint and height.
- A cat that has refused covered boxes before: the M1. An enclosed globe is a bigger ask than a hood.
- Odor containment above all: the Litter-Robot 4. A sealed globe holds more in than an open tray can.
- Three or more cats: neither on its own. Our box count page explains why one automatic box for a multi-cat house recreates the queue it was bought to remove.
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.
Neakasa M1 Open-Top Self-Cleaning Litter Box
Neakasa · Automatic litter box · Our score 8.6/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
The only automatic box here that publishes both its litter capacity and its noise figure, and the only open-top design -- which matters because cats prefer uncovered boxes.
Published specs
| Litter capacity | 7.17 L |
|---|---|
| Waste bin capacity | 11.23 L |
| Footprint / height | 23.26" x 20.67", 20.2" H |
| Entry height | 13.86" |
| Weight, empty | 22.81 lb |
| Cat weight range | 2.2-33 lb |
| Operating noise | Not more than 50 dB (published) |
Source: Neakasa -- M1 product page
11.23 L bin. Whisker's own guidance for its comparable drawer is emptying twice a week for two cats, i.e. roughly 3.5 days per two cats. Scale that to three and the bin needs emptying about every 4 days on published volumes -- an extrapolation from a competitor's published interval, not a measurement of this unit.
What the specs favor
- Publishes litter capacity (7.17 L) and waste bin capacity (11.23 L) -- almost nobody else does
- Publishes an operating noise figure of 50 dB or less
- Open top, which is the design cats are documented to prefer
- Takes ordinary clumping litter and ordinary bin bags -- no proprietary tray or liner
- Widest published cat weight range here at 2.2-33 lb
What they don't
- Open top means odor is not contained the way an enclosed drawer contains it
- 20.2 inches tall with a 13.86-inch entry -- a big step for an arthritic cat
- Bigger footprint than the enclosed units at 23.26 x 20.67 inches
Odor is your main problem. An open top vents into the room by design; if the smell is what you are trying to fix, an enclosed drawer with a carbon filter is the shape you want.
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
Is the Litter-Robot 4 or the Neakasa M1 better for a large cat?
Which one takes less space?
Which is quieter?
Which holds more waste?
Does an open-top automatic box smell more?
Sources
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 Litter-Robot 5
The $100 difference explained from Whisker's own spec sheets, with a clear verdict by household size.
- 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.
- 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.
- Best Litter Boxes for Large Cats (2026)
Manual litter boxes for big cats compared on published floor area, wall height and entry -- with the turn-around test that rules most boxes out.