Litter & Litter Boxes
Best Cat Litter for Odor Control
Many odor-control litters add fragrance. Feline vet guidelines written to help cats keep using the litter box recommend something different: an unscented, clumping litter, scooped every day [1].
We picked three clumping clay litters. Our top pick is unscented, which is our editorial call based on those guidelines. The two scented options are for you if you want fragrance, and we explain what the guidelines say about scent.
For most homes, the best cat litter for odor control is an unscented clumping clay, scooped every day. Clumping lets you lift the urine out of the box instead of covering it up, and in a 2018 field study cats chose clay or silica over wood pellets [5]. Fragrance is the trap: Cornell's Feline Health Center says most cats prefer unscented litter [2], and a cat that starts avoiding the box causes a far worse smell than any litter can fix.
Our 3 picks at a glance
- Best OverallDr. Elsey's Ultra Unscented Clumping Clay Cat Litter, 18 lbUnscented, clumping bentonite clay; our pick against the vet guidelinesCheck price on Amazon (opens Amazon in a new tab)
- Best Scented for Multi-Cat HomesFresh Step Advanced Odor Shield Multi Cat Clumping Litter, 2 × 18.5 lbCarbon plus Febreze scentCheck price on Amazon (opens Amazon in a new tab)
- Best Baking-Soda FormulaARM & HAMMER Clump & Seal Platinum Clumping Cat Litter, 18 lbBaking soda plus what the listing calls odor eliminators, online-only formulaCheck price on Amazon (opens Amazon in a new tab)
How we chose these litters
We searched Amazon for cat litter for odor control and read the top organic results. We left out deodorizer sprays, powders and additives, which aren't litter.
We compared them with the AAFP and ISFM guidelines on litter-box management [1]. Litter is only half the job: the box matters too, which is why we cover litter box enclosures separately. For smells beyond the box, see our pet odor eliminator guide and air purifiers for pet homes.
What the vet guidelines say about litter
The 2014 AAFP and ISFM house-soiling guidelines recommend a fine, sand-like, non-scented, clumping litter at least 1.25 inches (3 cm) deep. They note that cats often find aromatic litters and deodorizers offensive [1].
Those guidelines are about getting cats to use the box, not about how a home smells. Their routine is to remove waste at least once a day, top up litter as needed, and wash the box every one to four weeks, and they advise against liners, slotted grills and deodorizing powders [1]. In our view, that routine also does the most to keep smell down.
That is why our top pick is unscented. If you prefer a scented litter, we'd suggest changing one thing at a time. Because cats often find aromatic litters offensive [1], watch that your cat keeps using the box.
What cat litter is best for odor control?
Litter box smell comes mostly from urine that is still in the box. So the litter that controls odor best is the one that lets you remove urine completely, every day, and that your cat will keep using. That points to clumping litter. The AAFP and ISFM guidelines recommend a fine, sand-like, unscented clumping litter [1], and VCA's veterinary behaviorists note that clumping litters seem to be preferred by most, though not all, cats [4].
| Litter type | What happens to urine | What the research says about cats' preference | Watch for |
|---|---|---|---|
| Clumping clay (bentonite) | Forms a firm clump you scoop out | Fits the guideline description [1]; chosen over silica for defecation in a small 2018 study [5] | Heavy bags; dust and grain size vary by brand |
| Silica crystals or gel | Absorbed into the beads; most crystal litters don't clump, so urine stays until a full change | Used about as much as clay, and more than wood pellets, in phase one of the 2018 study [5] | Large crystals aren't the fine, sand-like texture the guidelines describe [1] |
| Pine or wood pellets | Pellets soak up urine and break down into sawdust you sift out | Least used of the three substrates in the 2018 study [5] | Hard pellet texture, far from fine and sand-like |
| Wheat, corn, walnut, tofu | Many are sold as clumping; how firm the clump is varies | We found no published preference studies | Some carry a natural scent; check it clumps firmly enough to lift out whole |
The 2018 study (Villeneuve-Beugnet and Beugnet) used 18 cats in its first phase and 12 in its second. We found no independent study that measured odor across litter types.
What cat litter controls odor the longest? No independent test we found answers that. Claims such as "14-day" or "15-day" odor control are the brands' own. In practice, the litter that stays fresh longest is a clumping one kept at depth and scooped daily, because the urine leaves the box with each clump. A non-clumping litter has to hold every day's urine until you change it.
Does scented litter control odor better? It changes what you smell, not what is in the box. The AAFP and ISFM guidelines warn that cats often find aromatic litters and deodorizers offensive [1], and VCA says some cats prefer plain clay without odor-control agents [4]. If you want to try a scented litter, VCA suggests offering it beside an unscented one in two identical boxes and letting your cat choose [4].
Dr. Elsey's Ultra Unscented Clumping Clay Cat Litter, 18 lb
Sold and shipped by Amazon.com.
Best Overall is our editorial call. The AAFP and ISFM guidelines describe four litter traits: fine, sand-like, non-scented and clumping [1]. Dr. Elsey's Ultra matches two of them, unscented and clumping, but its listing describes a medium grain rather than a fine, sand-like one. We picked it for the traits it matches.
The listing describes 100% bentonite clay that forms hard clumps and "helps prevent moisture from reaching the bottom of the tray". It says the litter suits single and multi-cat homes and sifting or mechanical litter boxes, and describes it as low tracking and 99.9% dust-free.
Good to know
- Unscented, as the vet guidelines recommend [1]
- Hard clumps for easy scooping, per the listing
- Suits sifting or mechanical boxes, per the description
Keep in mind
- The listing describes a medium grain; the guidelines prefer fine, sand-like litter
- "Hypoallergenic" and "ideal for ... allergies" are the listing's claims
Fresh Step Advanced Odor Shield Multi Cat Clumping Litter, 2 × 18.5 lb
Sold and shipped by Amazon.com.
If you want a scented litter, Fresh Step Advanced Odor Shield is our pick. The listing describes clay with activated charcoal, "Ammonia Block Technology" and Febreze scent, sold as two 18.5-lb boxes.
It claims 15-day odor control and that it "fights 100% of litter odors"; the listing's own footnotes define that as ammonia and fecal malodor and point to the pack for the guarantee terms. The title says it works with most automatic litter boxes.
Good to know
- Activated charcoal in the formula, per the listing
- Low-dust formula and ClumpLock clumping, per the listing
Keep in mind
- Scented (Febreze). The vet guidelines recommend non-scented litter [1]
- The 15-day odor claim is the brand's; terms are on the pack, not the listing
- Two heavy boxes, 37 lb in total
ARM & HAMMER Clump & Seal Platinum Clumping Cat Litter, 18 lb
Sold and shipped by Amazon.com.
This online-only Platinum formula pairs ARM & HAMMER baking soda with what the listing calls heavy-duty odor eliminators. The brand says Platinum formulas have 10% more odor eliminators than its base formulas, and the title claims 14-day odor control.
The listing describes it as 99.9% dust-free and low tracking, scented, and suitable for multi-cat homes and both traditional and robotic litter boxes.
Good to know
- Baking-soda formula (the brand cites more than 170 years of deodorizing)
- Works in robotic boxes, per the listing
- 99.9% dust-free and low tracking, per the listing
Keep in mind
- Scented ("Fresh Scent"). The vet guidelines recommend non-scented litter [1]
- The spec table lists odd package dimensions and two different weights; go by the 18 lb in the title
- "10% more" and "14-day" are the brand's claims
The three litters side by side
| Product | Scent | Material | Bag size | Works in automatic boxes |
|---|---|---|---|---|
| Dr. Elsey's Ultra | Unscented | Bentonite clay | 18 lb | Sifting or mechanical boxes, per description |
| Fresh Step Advanced | Scented (Febreze) | Clay + carbon | 2 × 18.5 lb | Most auto boxes, per title |
| ARM & HAMMER Clump & Seal Platinum | Scented (Fresh Scent) | Clay + baking soda | 18 lb | Robotic boxes, per listing |
Specs as stated on each Amazon listing, checked September 2026.
How to get rid of cat litter odor at the source
Every vet and welfare source we read puts the same habits ahead of any product:
- Scoop at least once a day, removing all feces and urine clumps [1] [3]. Break nothing up: lift each clump out whole.
- Keep the litter deep. The guidelines say at least 1.25 inches (3 cm) [1]; Cornell says most cats prefer about one to two inches [2]. Too shallow, and urine reaches the floor of the box, where scooping can't get it.
- Have enough boxes. Cornell and the ASPCA both give the rule of one box per cat plus one, in different parts of the house [2] [3]. Fewer boxes means each one gets more urine between scoops.
- Wash the box with mild, unscented soap or an enzymatic cleaner [3], and rinse well. The ASPCA warns that ammonia and bleach cleaners can encourage a cat to urinate in that spot again [3], and Cornell says products with ammonia or vinegar smell like urine to a cat [2].
- Skip plastic liners. The ASPCA and the AAFP and ISFM guidelines both advise against them [3] [1]; claws tear them and urine pools underneath.
- Replace a tired box. VCA advises replacing an old box that still holds odor after years of use [4]. A box that smells after a full wash is a box problem, not a litter problem; see our stainless steel litter box guide.
- Clean accidents fast. Cornell says cleaning works best soon after soiling, that odors must be neutralized rather than just deodorized, and that cats re-soil spots that smell of them [2]. An enzyme stain remover is built for that job.
A cover or cabinet hides the box but doesn't help. Cornell notes that from a cat's point of view, covers hold odors in [2]; our litter box enclosure guide covers how to vent one.
How often should you change cat litter?
Sources agree on daily scooping and differ a little on full changes. Here is what each says:
| Task | How often | Source |
|---|---|---|
| Scoop feces and urine clumps | At least once a day | AAFP and ISFM [1]; ASPCA [3] |
| Top up litter | As needed, to keep at least 1.25 in (3 cm) | AAFP and ISFM [1] |
| Empty, wash and refill the box | Every 1 to 4 weeks | AAFP and ISFM [1] |
| Full clean | At least weekly | ASPCA [3] |
| Wash the box; change clumping litter | Wash about weekly; change clumping litter every 2 to 4 weeks | VCA [4] |
| Full change | Often enough that the litter looks and smells dry and clean; more cats means more often | Cornell [2] |
With a non-clumping litter, urine can't be lifted out, so expect to be at the short end of these ranges.
A practical rule from those figures: one cat on clumping litter, a full change every two weeks; more cats per box or non-clumping litter, weekly.
Why does my litter box smell like ammonia?
A sharp ammonia smell means urine is staying in the box. The usual causes:
- Clumps breaking apart during scooping and leaving wet litter behind
- Litter too shallow, so urine soaks into the floor of the box
- Too few boxes for the number of cats [2]
- An old, scratched plastic box that holds odor even after washing [4]
- Waiting too long between full changes
Don't fight it with an ammonia-based cleaner. Cornell says those smell like urine to cats and can be irritating [2]. If the smell has suddenly got stronger, or you are finding bigger or more frequent urine clumps with the same routine, that can be a health change: Cornell lists kidney disease, thyroid disease and diabetes among the medical causes of litter box problems [2]. Ask your vet.
Can you put baking soda in cat litter?
You can, but the vet guidelines advise against it. The AAFP and ISFM guidelines recommend against deodorizing powders and note that cats often find deodorizers offensive [1]. VCA adds that some cats prefer plain clay with no odor-control agents at all [4]. We found no study showing that sprinkling baking soda reduces litter box odor more than daily scooping does.
If you want baking soda, a litter with it mixed in, like our ARM & HAMMER pick, avoids a layer of loose powder on top. If your cat starts avoiding the box afterward, go back to what worked.
Why is my cat peeing or pooping outside the litter box?
Rule out a medical cause first. VCA says urinary tract disease can cause it, as can pain or stiffness that makes the box hard to use, and recommends a vet exam and urinalysis [4]. Cornell adds that cats with medical conditions may not act sick [2].
Get help the same day if your cat, especially a male, is straining in the box and passing little or no urine. International Cat Care says urinary blockage is mainly seen in male cats and should be treated as an emergency [6].
Once your vet has ruled out illness, look at the box itself:
- Scent. A new scented litter or deodorizer is a common trigger, since cats often find them offensive [1].
- Cleanliness. Daily scooping is the baseline in every guideline [1] [3].
- Location. Cornell says cats want a spot that is quiet, private, away from their food and reachable 24 hours a day [2]. VCA warns against high-traffic areas and spots next to a furnace or washing machine [4].
- Number of boxes. One per cat plus one [2] [3].
- Stress. International Cat Care names indoor-only living and sharing a home with other cats as common stressors behind cystitis [6].
Clean every soiled spot thoroughly, because cats return to areas that smell of urine [2]. Our pet odor eliminator guide covers products for floors and furniture.
How to choose an odor-control litter
Unscented first
The AAFP and ISFM guidelines recommend non-scented litter and warn that cats often find aromatic litters offensive [1]. We'd try unscented before assuming you need fragrance.
Clumping
The guidelines recommend clumping litter and removing waste at least once a day [1].
Depth
The guidelines suggest a litter depth of at least 1.25 inches (3 cm) [1]. Buy enough to keep it there.
Your routine
The guidelines recommend scooping at least daily and washing the box every one to four weeks, and advise against deodorizing powders [1].
Which litter to buy
- Best Overall: Dr. Elsey's Ultra Unscented is our call: it matches the guidelines on scent and clumping, though not on grain size.
- Best Scented for Multi-Cat Homes: Fresh Step Advanced Odor Shield, if you want fragrance.
- Best Baking-Soda Formula: ARM & HAMMER Clump & Seal Platinum is the scented alternative built around baking soda.
Cat litter odor FAQ
What cat litter controls odor best?
None of our sources measured odor directly. The AAFP and ISFM guidelines, written to help cats keep using the box, recommend an unscented clumping litter, scooped at least once a day, with the box washed every one to four weeks [1]. We think that routine also does the most for smell. Our unscented pick is Dr. Elsey's Ultra.
Is scented cat litter bad for cats?
The AAFP and ISFM guidelines recommend non-scented litter and say cats often find aromatic litters and deodorizers offensive [1]. If you switch, watch for your cat avoiding the box.
How deep should cat litter be?
At least 1.25 inches (3 cm), according to the AAFP and ISFM guidelines [1].
How often should I change cat litter?
The guidelines say to remove waste at least daily, add litter as needed, and wash the box every one to four weeks [1].
Should I use litter deodorizer powder?
The guidelines advise against deodorizing powders, liners and slotted grills [1].
What is the best cat litter for multiple cats?
An unscented clumping litter, so each cat's urine leaves the box with every scoop [1]. The bigger lever is box count: Cornell and the ASPCA both recommend one box per cat plus one, in different parts of the home [2] [3]. Cornell also says the more cats using a box, the more often the litter needs a full change [2]. Scoop every box at least daily.
Is silica crystal litter good for odor control?
Silica absorbs urine into the crystals, but most crystal litters don't clump, so urine stays in the box until you change it. In a 2018 field study, cats used silica about as much as clay in the first phase, but chose clay over silica for defecation in the second [5]. Large crystals also aren't the fine, sand-like texture the AAFP and ISFM guidelines recommend [1].
Is pine litter good for odor control?
Pine pellets absorb urine and break into sawdust you sift out, and many owners like the smell of wood. The catch is the cat: in a 2018 field study, cats used clay or silica significantly more than wood pellets [5]. If you switch to pine, offer it in a second box beside the old litter first, as VCA suggests for any litter test [4].
Sources
- AAFP and ISFM Guidelines for Diagnosing and Solving House-Soiling Behavior in Cats, Carney HC et al., Journal of Feline Medicine and Surgery 16:579–598 (2014). journals.sagepub.com
- Cornell Feline Health Center — Feline Behavior Problems: House Soiling. vet.cornell.edu
- ASPCA — Addressing Litter Box Problems. aspca.org
- VCA Animal Hospitals — Cat Behavior Problems: House Soiling, Horwitz D and Landsberg G. vcahospitals.com
- Villeneuve-Beugnet V, Beugnet F. Field assessment of cats' litter box substrate preferences. Journal of Veterinary Behavior 25:65–70 (2018). sciencedirect.com
- International Cat Care — Feline idiopathic cystitis (FIC) in cats. icatcare.org