Litter-Robot 4 vs PETKIT Purobot Max 3 (2026)
Litter-Robot 4 vs PETKIT Purobot Max 3, side by side: price, cat weight limits, size, litter, waste capacity, warranty and return terms, from each brand's own pages.
How we chose: every figure on this page comes from Litter-Robot's (Whisker's) and PETKIT's own product, comparison and policy pages, checked Oct 17, 2026. We have not tested either box hands-on. How we research.
Both are rotating, self-cleaning litter boxes with an app. The Litter-Robot 4 costs more and supports more cats and heavier cats; the PETKIT Purobot Max 3 costs less, accepts more litter types and has the longer warranty. Here’s how the published specs compare.
Side by side
| Feature | Litter-Robot 4 | PETKIT Purobot Max 3 |
|---|---|---|
| Price on brand site | From $699 | $399.99 (seller’s compare-at price: $499.99) |
| Cats | Up to 4 cats, 3–25 lb | 3.3–22 lb, 6+ months old |
| Footprint | 22” x 27” | 24.4” W x 21.2” D |
| Height | 29.5” | 21.7” |
| Entry | 15.75” x 15.75” opening; 6.9” step height | 8.03” entrance height |
| Unit weight | 24 lb (empty) | 22 lb |
| Litter | Clumping clay recommended; some silica crystals can work | 99% of clumping litters, including clay, tofu, corn and bentonite |
| Waste capacity (brand claim) | Empty about every 8 days for 1 cat | 7 L (7.4 qt) bin; up to 15 days for 1 cat |
| App and Wi-Fi | Whisker app; 2.4 GHz Wi-Fi | PETKIT app; 2.4 GHz Wi-Fi |
| Power | 15V DC | 12V, 2A (24 W) |
| Noise | Not published in dB (“QuietSift”) | 35 dB |
| Carpet | Needs the Carpet Tray add-on | Not stated |
| Trial / returns | 90-day in-home trial | Return within 30 calendar days of delivery; buyer pays return shipping unless it’s a verified quality issue |
| Warranty | 1 year; 3-year WhiskerCare for $129 | 2 years (PETKIT warranty policy) |
| Link | See price at Litter-Robot for Litter-Robot 4 (opens in a new tab) | See price at PETKIT for PETKIT Purobot Max 3 (opens in a new tab) |
Capacity figures are each brand’s own claims under its own test conditions.
Which one fits your home?
Choose the Litter-Robot 4 if
- A cat weighs more than 22 lb (it's rated to 25 lb)
- You have 3–4 cats (Litter-Robot lists up to 4)
- You want the longest trial: 90 days in your home
Choose the PETKIT Purobot Max 3 if
- You want the lower price ($399.99 vs from $699)
- Your cat uses tofu, corn or another non-clay clumping litter
- You want the longer warranty (2 years vs 1) or a longer claimed emptying interval
- Height matters: it's 21.7" tall vs 29.5"
Either way, check your smallest cat: Litter-Robot says kittens under 3 lb should use semi-automatic mode, and PETKIT lists 3.3 lb and 6 months as minimums.
Running costs
- Litter-Robot 4: carbon filters (Litter-Robot suggests replacing them every 2–4 weeks), waste drawer liners and, optionally, a Whisker+ membership for extra history.
- PETKIT Purobot Max 3: clumping litter. PETKIT Care+, a paid upgrade, adds video history on PETKIT’s camera models.
For all eleven models we compare, see the automatic litter box buying guide.