| Bentonite Clay | Sodium bentonite clay | Absorbs urine and expands to form solid clumps around wet areas. | Excellent | Very good when cleaned regularly; unscented products depend mainly on absorption and ventilation. | Can produce dust; fine particles may track outside the box. | Mineral-based and generally not biodegradable; requires mineral extraction. | Multi-cat homes and buyers prioritizing strong clumping performance. |
| Silica Gel Crystals | Porous silicon dioxide crystals | Pores absorb liquid and trap odor molecules; moisture is retained in the crystals. | Usually non-clumping | Very good moisture and odor control when crystals are stirred and replaced as directed. | Typically low dust; larger crystals often reduce tracking. | Not biodegradable; silica gel is generally chemically stable and lightweight for transport. | Small spaces, odor-sensitive households, and lower-frequency replacement routines. |
| Tofu or Soy Fiber | Soybean fiber, tofu residue, or processed plant fiber | Plant fibers absorb urine and bind together into lightweight clumps. | Good to excellent | Good; performance varies with fiber structure, additives, and cleaning frequency. | Usually low dust and lightweight; pellets may scatter if the cat digs actively. | Made from renewable plant material and often biodegradable; disposal rules vary by region. | Buyers seeking a lightweight plant-based alternative with clumping ability. |
| Wood Pellets or Wood Fiber | Processed sawdust, softwood, or hardwood fiber | Pellets absorb liquid and gradually break down into damp sawdust. | Usually non-clumping | Moderate to good; natural wood scent may help mask odors. | Low dust when pellets remain intact; broken-down material may track. | Renewable and often biodegradable; responsible sourcing and moisture control are important. | Shelters, budget-conscious users, and households preferring larger pellets. |
| Recycled Paper | Recycled paper pellets, granules, or compressed fibers | Compressed paper absorbs moisture without forming conventional clay-like clumps. | Usually non-clumping | Moderate; requires frequent removal of wet or soiled areas. | Very low dust; pellets generally have low tracking. | Uses recycled fiber and is generally biodegradable; recycling or composting depends on contamination and local regulations. | Kittens, cats recovering from surgery, and dust-sensitive households. |
| Corn or Cassava | Corn, cassava starch, or other grain-based plant ingredients | Starch and plant particles absorb liquid and create scoopable clumps. | Good to excellent | Good when clumps are removed promptly; plant-based odor control varies by formulation. | Generally low to moderate dust; lightweight granules may track. | Renewable and potentially biodegradable; agriculture, moisture, and pest-control considerations apply. | Buyers wanting plant-based clumping litter with a familiar granular texture. |
| Walnut Shell | Ground walnut shells | Porous shell particles absorb moisture and may form clumps depending on particle size and formulation. | Moderate to good | Moderate to good; natural shell material helps reduce moisture-related odor. | Often low dust, but fine grades may track; dark color can make waste harder to inspect. | Uses an agricultural by-product and is generally biodegradable; avoid if household members or pets have relevant nut sensitivities. | Eco-conscious buyers who prefer a natural, darker-colored litter. |
| Grass Seed Fiber | Processed grass seed fiber and plant-based particles | Fine plant fibers absorb urine and bind into relatively light clumps. | Good | Good with regular scooping; natural odor control depends on moisture absorption. | Usually low dust, although fine particles can increase tracking. | Plant-based and generally biodegradable; supply depends on agricultural production and processing. | Lightweight-litter users and households seeking a renewable clumping material. |