As an Amazon Associate I earn from qualifying purchases.Independent research • Updated August 4, 2026
Side-by-side research

AS11 vs Litter-Robot 4 vs PuraMax 2 vs Neakasa M1 Plus

Compare the four finalists using the same factors and source-labeling standard.

FactorOriginal editorial illustration of the open-top AS11 AutoScooper 11AS11 AutoScooper 11Original editorial illustration of the Whisker Litter-Robot 4Litter-Robot 4Original editorial illustration of the PETKIT PuraMax 2PuraMax 2Original editorial illustration of the Neakasa M1 Plus open-top litter boxNeakasa M1 Plus
DesignOpen-top rolling/sifting designEnclosed rotating globeEnclosed rotating cylinder with low entranceOpen-top rolling/sifting design
DimensionsAbout 21.5 × 20.27 × 23.99 in, based on the archived AS11 manual associated with this ASIN22 × 27 × 29.5 in; 15.75 × 15.75 in entry24.41 × 21.18 × 21.73 in20.67 × 23.26 × 20.2 in
Cat-fit guidanceSeller/manual guidance commonly states 3–22 lb; verify the current listing and manualAutomatic mode for cats at least 3 lb; official guidance describes suitability through roughly 25 lb, while physical fit remains the practical limitManufacturer guidance: 3.3–22 lbManufacturer guidance: 2.2–33 lb
EntryOpen top; archived manuals list roughly 13.8 in from floor to entry15.75 × 15.75 in opening; 6.9 in step height7.87 in entry height; opening about 7.87 × 10.03 in13.86 in entry height; optional step may help some cats
Waste capacityPublic AS11 materials conflict between 7 L and 10 L; confirm the current variantOfficial FAQ lists a 5.5 × 13.5 × 9.25 in waste drawer7 L waste bin; manufacturer advertises up to 15 days for one cat11.23 L waste bin; manufacturer advertises up to 14 days for one cat
ConnectivityNo app or Wi-Fi features advertised for this ASIN2.4 GHz Wi-Fi and Whisker app for status, weight and usage insights2.4 GHz Wi-Fi and PETKIT appAndroid/iOS Neakasa app for monitoring and controls
Litter guidanceClumping bentonite or mineral litter; archived manuals warn against tofu and crystal litterMost clumping or scoopable litter; avoid non-clumping, newspaper and wood-pellet littersClumping clay, tofu or mixed litter within stated particle dimensionsFast-clumping scoopable litter; manufacturer states filter compatibility up to about 3 mm diameter and 10 mm length
Safety documentationInfrared and Hall sensors are described in archived AS11 materials; supervise setup and keep sensors cleanOmniSense/SafeCat system combines laser zones, weight sensors and anti-pinch software according to WhiskerPETKIT describes 11 sensors and an anti-pinch structureCurrent product materials describe six infrared-sensor pairs and four weight sensors
Important: Manufacturer weight limits do not guarantee comfortable physical fit. Measure the cat's body length, turning posture and mobility.

Choose AS11 when

You want a simple app-free open top and accept thinner documentation.

Read the AS11 review →

Choose Litter-Robot 4 when

Support depth, smart monitoring and a mature ecosystem justify the premium.

Read the Litter-Robot 4 review →

Choose PuraMax 2 when

A lower entrance and broad clumping-litter compatibility matter.

Read the PuraMax 2 review →

Choose Neakasa M1 Plus when

A premium open top and broad stated cat-fit range are the priority.

Read the Neakasa review →