Best Litter for Litter-Robot: Whisker's Official Guidance

Whisker’s answer is short. On its product-page FAQ it says: “The best litter for Litter-Robot is clumping clay litter.” The LR4, LR5 and EVO manuals all say the sifting system needs clumping litter, and all recommend a high-quality clay-clumping litter. Whisker’s own litter is the one it names first. The LR5 and EVO manuals call it GreatLitter. Whisker’s litter guide says it is now sold as Lit Premium Cat Litter (“formerly GreatLitter”).

What the manuals say, model by model

Litter-Robot 4

• p. 12 (Litter): The sifting system “requires clumping litter to work properly”. Whisker recommends a high-quality clay-clumping litter. Beads and crystals small enough to pass through the screen will also work, but they need periodic changing. Translucent or white litter, most often seen in crystal litter, may affect the litter-level and Drawer Full Indicator (DFI) readings.
• p. 12 (Do not use): strictly absorbent, non-clumping, loose-clumping or newspaper-based litters, and wood-based pellets.
• p. 12 (Amount): fill to the raised MAX Fill Line, approximately 3.6–4.5 kg by weight or 4 L by volume.
• p. 13: if you use a litter not listed, Whisker asks you to contact its Customer Experience team.
• p. 35 (FAQ): lightweight litters such as corn or wheat “may not pass through the screen effectively”. This FAQ also adds pine-based litters to the list of litters that do not work.

Litter-Robot 5

• p. 12: the same clumping-litter requirement, with GreatLitter named as an example. Crystals that pass through the screen also work, with “more frequent changing” required. Translucent or white litter may affect the LitterLevel and DFI readings. The do-not-use list matches the LR4’s p. 12 list.
• p. 13 (Amount): approximately 1 gallon (4 L) by volume. Whisker notes that 1 gallon of GreatLitter weighs about 10 pounds (4.5 kg), and that natural or lightweight litter may weigh less.
• p. 43 (FAQ): Whisker says the Litter-Robot “works well with almost any clumping or scoopable litter”.

Litter-Robot EVO

• PDF p. 10 (printed p. 8): the same requirement and do-not-use list as the LR5. Translucent or white litter may affect DFI accuracy.
• PDF p. 11 (printed p. 9): approximately 0.8 gallons (3 L) by volume. Whisker says that much GreatLitter weighs about 8.8 pounds (4 kg).
• PDF p. 38 (printed p. 36): the same FAQ answer as the LR5, plus “approximately 8.8 pounds of litter” to the MAX Fill Line.

Whisker’s product pages for all three models carry the same FAQ. It recommends “a high-quality, standard-weight, clay-based clumping litter, such as Lit Premium Cat Litter”, and adds that “alternative, plant-based litters typically do not work”. Lit Premium was $30 for 20 lb on the LR4 page as of 2026-11-02.

What Whisker tells you to avoid

Across the manuals, FAQs and Whisker’s litter guide, Whisker rules out or does not recommend:

• Non-clumping, loose-clumping or strictly absorbent litter. The sifting system cannot separate waste that doesn’t clump.
• Newspaper or paper-based litter.
• Wood pellets and pine-based litter (pine is listed in the LR4 manual, p. 35). Whisker’s guide also marks pea-husk and other pellet-shaped litters as not sifting properly.
• Translucent or white crystal litter on LR4, LR5 and EVO, because of the sensors. Whisker’s guide says one crystal litter that worked in the older Litter-Robot 3 is not recommended for the current models.
• Lightweight litters, with care. The LR4 manual warns about corn and wheat. Whisker’s guide marks one corn-based clumping litter as working, though it “may need more frequent changes”, and another corn-based litter as not recommended. For tofu, the guide says some brands work depending on clumping and particle size, and lists one tofu litter as not sifting properly.

Besides its own litter, the guide names a co-branded clumping clay litter made for Litter-Robot (Tidy Cats Designed for Litter-Robot), and a longer brand-by-brand list. The LR5 and EVO manuals point you to that guide if your litter isn’t listed; the LR4 manual points you to Whisker’s support.

Tips from the manuals

• Switching from your old box. All three manuals suggest keeping the litter you already use at first, as long as it clumps. Whisker says introducing a new litter at the same time as a new box “may increase their anxiety”. If you use non-clumping litter now, Whisker says you will need to switch to a clumping type.
• Slow-setting litter. The LR4 manual (p. 24) says to extend the Cycle Delay when using lower-quality clumping litter that needs more time to set up. The default delay is 7 minutes, and you can choose 3, 7, 15, 25 or 30 minutes.
• Don’t overfill. Fill only to the MAX Fill Line; the LR4 FAQ says extra litter is pushed into the drawer in the first few cycles.

If your cat has a health condition that affects litter choice, ask your veterinarian. For problems with the unit, contact Whisker’s support.

To compare other makers’ rules, see best litter for self-cleaning litter boxes. Also see the Litter-Robot 4 page, running costs and Litter-Robot alternatives.

Bottom line

For the Litter-Robot 4, 5 and EVO, Whisker asks for clumping clay litter, and names its own Lit Premium (formerly GreatLitter) first. Avoid non-clumping, paper, pine and pellet litters, and translucent or white crystals. Treat corn and tofu as brand-by-brand cases. Fill to the MAX line: about 4 L for the LR4 and LR5, and about 3 L for the EVO.