What is the best cat litter for odor control?

Across the reviewers we read, hard-clumping clay litters with sodium-bicarbonate or activated-charcoal additives — Arm & Hammer Clump & Seal SLIDE Platinum and the Fresh Step Heavy Duty / Extreme lines with Febreze — get the most consistent praise for odor control. Unscented hard-clumping clay like Dr. Elsey's also performs well if you scoop daily, since odor control depends as much on clump integrity as on added fragrance.