Litter-Robot EVO vs Litter-Robot 4 (2026)
Litter-Robot EVO vs Litter-Robot 4: price, cat limits, footprint, entry and step height, and the features Whisker lists for each, side by side.
How we chose: every figure on this page comes from Litter-Robot's product pages and Whisker's own Litter-Robot comparison chart, checked Oct 17, 2026. We have not tested either box hands-on. How we research.
The EVO is Litter-Robot’s smaller, lower-priced model, aimed at homes with one or two cats. The Litter-Robot 4 supports more and bigger cats and has a few features the EVO doesn’t list. Both come with Litter-Robot’s 90-day in-home trial and a 1-year warranty.
Side by side
| Feature | Litter-Robot EVO | Litter-Robot 4 |
|---|---|---|
| Price on brand site | From $599 | From $699 |
| Cats | Up to 2 cats, 3–19 lb | Up to 4 cats, 3–25 lb |
| Footprint | 20.6” x 24.3” | 22” x 27” |
| Exterior height | 27.6” | 29.5” |
| Globe opening width | 14.85” | 15.75” |
| Interior globe height | 14.5” | 16.5” |
| Step height | 5.6” | 6.9” |
| Weight (empty) | 21.5 lb | 24 lb |
| Emptying (brand claim) | About every 7 days for 1 cat | About every 8 days for 1 cat |
| Waste level sensing | Only notifies when full | Monitors any level |
| Use on carpet | Carpet Tray built in | Needs the Carpet Tray add-on |
| Screen | LCD color screen plus LED control panel | LED control panel (no LCD screen listed) |
| Trial and warranty | 90-day in-home trial; 1 year; 3-year option $99 | 90-day in-home trial; 1 year; 3-year WhiskerCare $129 |
| Link | See price at Litter-Robot for Litter-Robot EVO (opens in a new tab) | See price at Litter-Robot for Litter-Robot 4 (opens in a new tab) |
Features Whisker lists for both
Wi-Fi-connected Whisker app, Whisker+ compatibility, a built-in weight scale (SmartScale), cat identification by weight in 2+ cat homes, 7-day weight and activity history, bathroom habit tracking, 7-day offline data storage, a 15V DC power supply and compatibility with a backup battery and ramp.
Features Whisker lists for the Litter-Robot 4 but not the EVO
LitterLevel sensing, LitterHopper compatibility, a scratch-resistant globe liner and an adjustable LED night light. On Whisker’s chart those rows are blank for the EVO.
Which one fits your home?
Choose the EVO if
- You have one or two cats, all under 19 lb
- Space is tight: it's 1.4" narrower and 2.7" shallower
- It will sit on carpet (Carpet Tray built in)
- You want a lower step (5.6")
Choose the Litter-Robot 4 if
- A cat weighs 19–25 lb, or you have 3–4 cats
- You want waste-level updates before the drawer is full
- You want a night light or LitterHopper compatibility
For bigger cats (up to 30 lb) or up to five cats, Litter-Robot’s newer Litter-Robot 5 starts at $799. See the full automatic litter box buying guide.