Which is better for a two-cat household?

The EVO covers 2 cats and costs $100 less. The 4 also works for 2 cats and gives you up to 8 days between empties, so pick it if you would rather empty the drawer less often.

Which handles more cats?

The Litter-Robot 4, rated for up to 4 cats. The EVO is rated for up to 2 cats weighing 3-19 lbs.

Is the Litter-Robot 4 worth $100 more?

Only if you have 3 or 4 cats or want the extra day between empties. For 1 or 2 cats, the EVO does the same job for less.

Which fits a small apartment better?

The EVO. Its footprint is about 20.6" x 24.3", against 22" x 27" for the 4, and Whisker markets it for small spaces.

Which has better odor control?

The EVO lists a sealed drawer with multi-layered carbon filtration. The 4 uses a carbon filter in its drawer. Both control odor; the EVO's sealed design is the more elaborate setup.

Do both work with the Whisker app?

Yes. Both connect to the Whisker app for visit monitoring and weight tracking. The EVO adds a full-color display on the unit.

Whisker Litter-Robot 4 vs Litter-Robot EVO

Buy the Litter-Robot EVO if you have one or two cats and want the lower price: $599 at Best Buy as of November 5, 2026, versus $699 at Amazon for the Litter-Robot 4. Buy the Litter-Robot 4 if you have three or four cats or want the longest stretch between drawer empties. The EVO is the newer, more compact design, but the 4 handles a bigger household for $100 more.

Today the Litter-Robot EVO costs $100.00 less at its best price.

Ask our shopping agent

It checks today's price at every store, compares the alternatives and answers in about a minute.