Litter-Robot 5 vs Litter-Robot 4 vs EVO: Which Litter-Robot to Buy in 2026

Whisker now sells three Litter-Robots, and the right one depends mostly on your cats’ size and number. The Litter-Robot EVO (about $599) suits one or two cats of 3–19 lb in a smaller space. The Litter-Robot 4 (about $699–749) covers up to four cats of 3–25 lb and is still the best all-rounder. The Litter-Robot 5 ($799 at Whisker) raises the limits to five cats and 30 lb and adds WasteID health tracking, which needs a subscription.

We haven’t tested these boxes ourselves. This comparison uses Whisker’s published specs and prices, Amazon listing text, and hands-on results from WIRED and Tom’s Guide, which we name wherever they appear. Prices are typical street prices from dated sources, not live Amazon prices. Check today’s price before you buy.

Litter-Robot 5 vs 4 vs EVO specs

All three use the Whisker app and clumping clay litter, and Whisker prices their liners and carbon filters the same. See every box side by side on the comparison chart.

Weight and cat limits

This is the first thing to settle. Whisker rates the EVO for up to two cats of 3–19 lb, the LR4 for up to four of 3–25 lb, and the LR5 for up to five of 3–30 lb.

Treat the upper limits as firm. A 20-lb cat rules out the EVO, and a cat near 25 lb is better served by the LR5’s extra headroom: 17.5 in inside against 16.5 in for the LR4 and 14.5 in for the EVO. If you’re unsure, check your cat’s weight and length in the safety checker.

The minimum is the same on all three. Whisker lists 3 lb for automatic mode, and below that says to use semi-automatic mode: leave the robot powered off and cycle it yourself. Our kitten guide covers the transition.

For cat counts, remember that a rating is a maximum, not a target. The AAFP’s guidance for regular boxes is one per cat plus one. WIRED notes that automatic boxes reduce the need for multiple options, but suggests keeping the old box out. Our box calculator helps you plan.

Sensors: why the EVO is different

The LR4 pairs a laser curtain with weight sensors, and Whisker says the LR5 uses multiple lasers plus weight sensors and anti-obstruction detection. Two kinds of sensing give the robot more than one way to notice a cat.

Whisker says the EVO relies on weight sensors to detect a cat entering and leaving. Its entrance still stays open: the EVO is one of WIRED’s picks, and WIRED only recommends boxes that stay open during cycling. But a weight-only box depends on one signal, which is one more reason to respect its 3 lb minimum. Our safety explainer goes into the details.

WasteID and Whisker+

The LR5’s headline feature is WasteID, which Whisker says distinguishes urine from stool visits. It’s aimed at owners who want a closer record of their cats’ bathroom habits than visit counts and weights alone.

There are two catches:

• It needs a subscription. WasteID and cat identification need Whisker+, which WIRED puts at about $80 a year. Check Whisker for current plans.
• It took time to work. In WIRED’s testing, WasteID and weight-based cat ID worked only intermittently for the first four months, then improved markedly after firmware updates.

The Amazon listing sells the LR5 as a Protection & Insights Bundle, with a 3-year warranty and six months of Whisker+. We couldn’t capture that bundle’s price, so compare it against Whisker’s $799 robot price on the day.

Whisker also sells an LR5 Pro at $999 with dual AI cameras. WIRED says it needs Whisker+ for reliable AI features. We don’t cover it separately.

Controls and daily use

WIRED found the LR5’s touchscreen finicky and preferred the LR4’s physical buttons. That’s a small thing until you’re resetting a cycle with litter on your hands.

On daily use, all three are low-effort, with different strengths:

• EVO: WIRED’s single-cat tester emptied it about once a week and found it virtually odor-free and basically silent. Its unit arrived without the liners it should include, and waste sometimes stuck to the globe’s ceiling. WIRED says it has no litter-level sensing or LitterHopper support, so you top up by hand.
• LR4: WIRED names it its pick for automatic litter refilling with the optional LitterHopper ($129 at Whisker), and likes the app. Tom’s Guide found the app tells cats apart by weight.
• LR5: WIRED’s tester emptied it about every 10 days with two cats, and WIRED suggests adding Whisker’s ramp and mat.

Reliability

The LR4 has the longest record of the three, and it has known wear points. After nearly two years, WIRED’s unit sometimes sensed “ghost cats” and reported a full drawer when it was half full, and the LitterHopper intermittently stopped working. Tom’s Guide’s LR4, used for more than a year, was still holding up but sometimes squeaked, so plan on regular maintenance. The EVO and LR5 are newer, so there’s less long-term data on either. The Amazon LR5 listing first appeared on October 16, 2026. Our troubleshooting guide covers the common errors.

What about the Litter-Robot 3?

Whisker’s Litter-Robot 3 Connect page now says the model is no longer available. If you see one secondhand, two specs matter: it needed cats of at least 5 lb for automatic mode, against 3 lb on current models, and its entry was 10.25 × 15.25 in. For kittens and small cats in particular, a current model is the better choice.

Prices and running costs

Whisker’s prices on November 12, 2026 were $599 for the EVO, $699 for the LR4 and $799 for the LR5. WIRED’s November 6 price box showed the LR4 at $749 on Amazon. Whisker’s site carried a holiday banner for “$150 off select Litter-Robot bundles,” so compare bundle prices with the robot-only price before you buy. Our Black Friday guide explains how to judge a deal.

Running costs are nearly identical, because all three use Whisker liners (25 for $25), carbon filters (6 for $30, one filter per cat) and clumping litter at the same prices. With our default assumptions, about four liners, one filter and 10 lb of litter per cat per month, that’s about $177 a year for one cat.

Optional OdorTrap packs are excluded. Adjust the numbers in the cost calculator. Whisker supplies on Amazon include drawer liners, the LR4 carbon filter 6-pack and a cleaning supply kit; check each listing for model fit. More on the accessories page.

Which Litter-Robot to buy

Not set on Whisker? Our Litter-Robot alternatives and Litter-Robot 4 vs PETKIT PuraMax 2 cover cheaper options, and the litter box matcher sorts every box by your cats and budget.

Verdict

Buy the Litter-Robot EVO if you have one or two cats under 19 lb. It’s the cheapest Litter-Robot, takes the least space, and WIRED found it quiet and odor-free. Accept weight-only sensing and topping up litter yourself.

Buy the Litter-Robot 4 if you have three or four cats, a cat up to 25 lb, or want the LitterHopper. It’s the best-supported model, with a laser curtain, physical buttons and the longest test record, wear issues included.

Buy the Litter-Robot 5 only if you need its limits, five cats or a cat over 25 lb, or you specifically want WasteID and will pay for Whisker+. It’s a capable robot, but for most homes the extra money buys features WIRED found took months to settle.

Check today’s Litter-Robot 4 price, EVO price or Litter-Robot 5 bundle price before you decide.