Whisker Litter-Robot 4

$699 MSRP, per whisker.com — matched at the same price on PetSmart and Best Buy. Whisker launched a full next-generation line in October–November 2025 that now sells alongside the 4: Litter-Robot EVO ($599, a simplified/entry model), Litter-Robot 5 ($799), and Litter-Robot 5 Pro ($899, adds dual AI cameras with facial recognition and WasteID waste-type detection). The 4 remains Whisker's mid-tier holdover rather than a discontinued model.

Litter-Robot 4 uses Whisker's SafeCat System with Omnisense Detection — lasers, weight sensors, and anti-obstruction technology — to prevent the cleaning cycle from running while a cat is inside or nearby. SmartScale logs each cat's weight to identify individual cats in multi-cat households. Note: it requires 2.4GHz WiFi specifically; Whisker's spec sheet states the 5GHz band is not supported.

The Litter-Robot 4's SmartScale system weighs each cat at every visit, letting the companion app track and distinguish up to four individual cats sharing one unit by weight alone — a specific multi-cat identification capability most single-sensor automatic litter boxes lack. Whisker's own spec sheet also states the unit requires 2.4GHz Wi-Fi specifically, since the 5GHz band isn't supported. With the EVO/5/5 Pro line now the current lineup, the 4 sits as the known-quantity middle option — one reviewer who'd run a 4 for three years used it as the baseline when testing the 5, noting it may be worth sticking with the 4 until the 5's newer features (like dual-camera WasteID) are fully proven out.