Litter-Robot 4 specs
| Brand | Whisker |
|---|---|
| Mechanism | Rotating globe |
| Cat weight (automatic mode) | 3–25 lb. Whisker's FAQ gives 3–25 lb; WIRED lists "4 pounds minimum, no maximum". |
| Cats per box | Up to 4 |
| Kittens & small cats | Under 3 lb: Whisker says leave it powered off and start cycles yourself ("semi-automatic" mode) until the kitten weighs 3 lb. |
| Safety sensors | Laser curtain, Weight. Laser curtain plus weight sensors detect a cat entering and leaving and pause the cycle (Whisker). |
| Entrance during cleaning | Stays open. WIRED only recommends boxes that stay open during cycling; the LR4 is one of its picks. |
| Litter | Clumping. Standard-weight clumping clay recommended. Some silica crystals that pass the screen work; translucent or white litter can confuse the litter-level sensor. |
| Waste drawer | Whisker says the drawer may need emptying as rarely as once every 8 days. |
| Entry | 15.75 × 15.75 in. 15.75 × 15.75 in entry, 16.5 in interior height (Whisker). |
| Footprint | 22 × 27 in, 29.5 in tall |
| Unit weight | 24 lb |
| App / Wi-Fi | Yes (Wi-Fi (Whisker app)) |
| Odor control | Sealed waste drawer with a carbon filter; optional OdorTrap packs. |
| Consumables | Drawer liners ($25 for 25 at Whisker), carbon filters ($30 for 6) and optional OdorTrap packs ($30 for 6). Whisker suggests a new filter and packs every 2–4 weeks. |
| Warranty | 1-year WhiskerCare; 3-year extended plan available from Whisker |
| Price tier | $$$ Premium ($550–$799). $699 at Whisker (Nov 12, 2026); WIRED's Nov 6, 2026 price box showed $749 at Amazon. |
- Weight range: Whisker's FAQ says 3–25 lb and up to 4 cats; WIRED's spec box says 4 lb minimum and no maximum. We use Whisker's figures.
- Height 29.5 in is from the Amazon listing (27 × 24.25 × 29.5 in with the step); Whisker lists only the 22 × 27 in footprint.
- Whisker suggests replacing the carbon filter and OdorTrap packs every 2–4 weeks, depending on use.
Running costs: with our defaults, consumables for one cat come to about $9.00 a month plus litter. See the full breakdown in the cost calculator.
Versions and bundles
Each option is a separate Amazon listing. Prices, where shown, are dated snapshots, not live prices.
| Option | What's different | Price |
|---|---|---|
| Litter-Robot 4, black (robot only) | Our pick: the base unit | Check price |
| Litter-Robot 4, white | Same robot in white | Check price |
| Complete Bundle, black (about $899) | Adds 6 OdorTrap refills, 50 liners, ramp, mat and fence | Check price |
| Protection & Insights Bundle, black | 3-year warranty and 6 months of Whisker+ | Check price |
Specs are compiled from manufacturer pages, Amazon listings and independent reviews and can change between production runs. Confirm the weight range and what's in the box on the Amazon page before buying.
We haven’t tested the Litter-Robot 4 ourselves. This review draws on long-term testing by WIRED, which has used one for close to two years, and by Tom’s Guide, which ran one for more than a year alongside three rival boxes. Specs come from Whisker and the Amazon listing.
The Litter-Robot 4 is the benchmark self-cleaning box: a rotating globe that sifts clumps into a sealed drawer, rated for up to four cats from 3 to 25 lb. It costs about $699 at Whisker, and WIRED’s November 2026 price box showed $749 at Amazon, so check the price before you buy.
Who it’s for (and who should skip it)
It’s for homes with two to four cats, or one big cat that needs a roomy entry. The 15.75 × 15.75 in opening and 16.5 in interior height suit most large breeds, and WIRED calls the Whisker app great.
Skip it if you have one or two average-size cats and not much floor space. The Litter-Robot EVO does the same job for $100 less in a smaller footprint, as long as each cat weighs 3 to 19 lb. On a tighter budget, the PETKIT PuraMax 2 costs about half as much (see Litter-Robot 4 vs PETKIT PuraMax 2). Cats that refuse hoods may prefer the open-top Neakasa M1 (see Neakasa M1 vs Litter-Robot 4).
How it cleans, and how safe it is
After a cat leaves, the globe rotates to sift waste into the drawer. Whisker says a laser curtain and weight sensors detect a cat entering and leaving and pause the cycle. WIRED only recommends boxes that stay open while they cycle, and the LR4 is one of its picks.
The minimum for automatic mode is 3 lb, down from 5 lb on the discontinued Litter-Robot 3. Under 3 lb, Whisker says to leave the robot powered off and run cycles yourself until the kitten is big enough. Our cat safety checker compares your cat’s weight, age and length with these limits.
Sensors age, and long-term testing shows it. After nearly two years, WIRED’s unit sometimes sensed “ghost cats” and reported a full drawer when it was only half full. Tom’s Guide’s unit was still holding up after more than a year, but it sometimes squeaked while cleaning, a sign it needed maintenance. Neither is a safety failure, but plan on regular cleaning. Our troubleshooting guide covers the usual fixes.
Living with it
Getting your cat to use it
Whisker says over 95% of cats acclimate, a figure it bases on return reasons. In Tom’s Guide’s test, the cats used the LR4 30 times in one week, almost triple their visits to Leo’s Loo Too, though the open-top Neakasa M1 got more use still. Keep the old box out during the switch. Our transition guide walks through it.
Litter, emptying and odor
Use standard-weight clumping clay. Translucent or white litter can confuse the litter-level sensor. More in best litter for self-cleaning litter boxes.
Whisker says the drawer may need emptying as rarely as once every 8 days. The drawer is sealed and has a carbon filter, and you can add OdorTrap packs. Whisker suggests replacing both every 2–4 weeks. Tom’s Guide found the box can still cycle when the app says the drawer is full, so empty it when you get the warning.
App, extras and size
According to WIRED and Tom’s Guide, the app tracks visits and weight, tells cats apart by weight, and warns when litter is low or the drawer is full. There’s an interior night light and an elevated step. The optional LitterHopper ($129 at Whisker) refills litter automatically. That’s why WIRED calls the LR4 its best box with litter refilling, though the LitterHopper intermittently stopped working in WIRED’s long-term test.
The footprint is 22 × 27 in. The Amazon listing gives 29.5 in tall with the step and 24 lb.
Running costs
Consumables at Whisker’s prices, with our cost model’s assumptions:
| Item | Price (source) | Our usage assumption |
|---|---|---|
| Drawer liners | $25 for 25 (Whisker) | about 4 per cat per month |
| Carbon filters | $30 for 6 (Whisker) | 1 per cat per month |
| OdorTrap packs (optional) | $30 for 6 (Whisker) | 1 per cat per month |
| Clumping clay | $22.99 for 40 lb (Chewy) | 10 lb per cat per month |
That’s about $14.75 a month for one cat, or roughly $177 a year, before OdorTrap packs. Over five years, including the robot at $699, we estimate about $1,584 for one cat and about $2,469 for two. Use your own numbers in the cost calculator.
What you’ll need beyond the box
- Litter: Dr. Elsey’s Ultra unscented, 40 lb, a standard-weight clumping clay.
- Liners: Litter-Robot drawer liners, 25-pack.
- Odor: LR4 carbon filters, 6-pack (about $30), or the filters plus OdorTrap bundle.
- Cleaning: Whisker’s cleaning supply kit (about $85 in a listing snapshot) bundles wipes, liners, spray and OdorTrap refills.
- Mat: a Gorilla Grip 35 × 23 in mat.
If you’d rather buy once, the Complete Bundle (about $899) adds six OdorTrap refills, 50 liners, a ramp, a mat and a fence. The robot also comes in white.
Warranty is one year of WhiskerCare, with a three-year plan from Whisker. The Amazon listing mentions a 90-day in-home trial.
Bottom line
The Litter-Robot 4 is still the safest, best-supported self-cleaning box you can buy on Amazon, with a large entry, laser and weight sensing and room for four cats. The downsides are price, about twice a PuraMax 2, and sensor quirks as it ages. For several cats or a big one, it’s the box we’d buy; for one or two average-size cats, the EVO saves money and space. Want more health data? Compare it with the Litter-Robot 5 in Litter-Robot 5 vs 4 vs EVO, or run your home through the litter box matcher. When you’re ready, check the Litter-Robot 4 price.
Litter and supplies for the Litter-Robot 4
Litter, liners, odor refills and mats sold on Amazon that fit this box. Check the listing confirms your exact model before you buy.
- Liners & bagsLitter-Robot waste drawer liners by Whisker, 25-packOfficial Whisker
Custom-fit 9–11 gallon liners; Whisker's white redesign gives more accurate drawer-level readings. The Amazon listing showed as unavailable in one snapshot; Whisker's cleaning supply kit also includes 25 liners.
- Odor controlLitter-Robot 4 carbon filters by Whisker, 6-packOfficial Whisker
Absorbs odor from the waste drawer; Whisker suggests a new filter every 2–4 weeks.
- Odor controlLitter-Robot odor-reducing bundle: 6 carbon filters + 6 OdorTrap packsOfficial Whisker
Both odor consumables in one order for the LR4. Listed for the Litter-Robot 4; check carbon filter fit for the EVO and LR5 on Whisker's site.
- Supply kitWhisker Litter-Robot cleaning supply kit: 30 wipes, 25 liners, spray, 6 OdorTrap refillsOfficial Whisker
A few months of liners and odor packs plus the cleaner Whisker recommends for the globe.
- LitterDr. Elsey's Ultra unscented clumping clay cat litter, 40 lbCompatible, third-party
Unscented, hard-clumping, standard-weight clay: the type Whisker recommends and most globe and drum boxes are tuned for. Not for ScoopFree crystal trays. Check your box's sifter: PETKIT asks for granules under 0.5 in.
- Litter matGorilla Grip cat litter mat, 35 × 23 inUniversal fit
Big enough to catch scatter from most globe boxes; textured backing stays put.
- Litter matGorilla Grip cat litter mat, extra large, 40 × 28 inUniversal fit
The size we'd put under open-top boxes, which both WIRED and Tom's Guide found fling more litter.
- Litter matiPrimio jumbo cat litter trapper mat, 32 × 30 inUniversal fit
Honeycomb two-layer mat with a waterproof layer, for cats that kick litter far.
Compatibility checked November 2026. More in our litter and supplies guide.
Featured in our guides
- The 8 Best Self-Cleaning Litter Boxes of 2026, Ranked for Safety and Value
- The Best Self-Cleaning Litter Box for Multiple Cats in 2026
- The Best Self-Cleaning Litter Box for Large Cats in 2026
- The Best Self-Cleaning Litter Box for Senior Cats in 2026
