How to Switch Cat Litter Without Accidents
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Maybe the old litter is too dusty, too heavy, or no longer sold. Maybe you want a plant-based litter, or you are moving to a new kind of box. Whatever the reason, cats notice a new litter at once, and some answer by going on the rug instead. This guide shows how to switch cat litter slowly, how to tell whether your cat accepts it, and what to do if they refuse.
How we wrote this: the switching method comes from Best Friends Animal Society’s guide to getting your cat to use the litter box, and the setup and troubleshooting advice from Battersea’s guide to the best litter tray setup and its guide to cats toileting around the house. The health notes come from Best Friends’ page on medical causes of litter box problems. All were checked on 1 November 2026. We did not test any litters or boxes ourselves, and we do not show prices or ratings.
Health first. If your cat strains in the box, cries while peeing, passes blood, goes in and out of the box often with little result, or stops using the box at all, call your vet the same day. Best Friends warns that urinary problems can be life threatening for cats. A cat that is unwell may avoid the box whatever litter is in it, so do not treat that as a litter problem.
Why a litter change can upset your cat
Cats are fussy about where they go to the toilet. Battersea says they want somewhere quiet, private and safe, with room to dig and cover their waste, and that strong smells, noise or a cramped tray can put them off. Best Friends points out that a cat’s sense of smell is many times stronger than ours, so even a light scent can be too much and lead a cat to avoid the box.
A new litter changes two things at once: how it smells and how it feels under the paws. Battersea lists a change in litter, including a different brand, among the things that can unsettle a cat, and its guide to toileting problems names a litter that smells strange or has a new texture as one possible cause of stress that shows up as accidents around the house.
That is why Battersea advises sticking with one litter once your cat uses it with confidence, and Best Friends suggests keeping the litter your cat knows where you can. If you must change, go slowly.
Before you switch
- Know why you are switching. If the goal is less odor, daily scooping often does more than a new litter. See how often to change cat litter and our best cat litter for odor control guide first.
- Pick a litter close to what cats like. Battersea says most cats like a soft, sand-like surface and suggests a soft, unscented litter that is gentle on paws. Best Friends also prefers unscented litter. A move from one fine clumping litter to another is usually easier than a move to pellets or crystals. Our types of cat litter guide compares clay, crystal, pine, corn and paper.
- Choose a calm week. Do not change litter in the same week as a house move, a new pet, building work or a stay away from home.
- Keep the old litter. You will need it for a few weeks, so do not throw it out when the new bag arrives.
Method 1: a second box with the new litter (best for wary cats)
Best Friends suggests this first: set up an extra box with the new litter and see whether your cat uses it. It lets your cat choose, and the old box stays as a safe fallback.
- Set up the second box next to the first. Use the same kind of box if you can, so the litter is the only thing that changes. A large open box such as the IRIS USA High-Sided Litter Box works well as a second box.
- Fill it with the new litter. Best Friends suggests a depth of about 3 inches so your cat can dig and cover. Battersea gives a minimum of 3 to 4 centimeters.
- Keep both boxes clean. Scoop both at least once a day. A dirty new box will be rejected for the wrong reason.
- Watch which box gets used. If your cat uses the new box, even only some of the time, start the mix method below in the old box.
- Retire the old box last. Once your cat uses the new litter every time for a week or more, the old box can go, or stay as one of your extra boxes.
Method 2: mix the new litter into the old
Best Friends describes the next step: once your cat uses the new litter, add it to the original box little by little until the old litter is fully replaced. If you have only one box, you can start here, but go slower. A plan that suits most cats:
- Days 1 to 3: about three quarters old litter, one quarter new, mixed through the box.
- Days 4 to 6: about half and half.
- Days 7 to 9: about one quarter old, three quarters new.
- Day 10 on: new litter only, if your cat has kept using the box normally.
These steps are a guide, not a rule. Move to the next step only when your cat has used the box normally at the current mix for a few days. If your cat hesitates, stay at the current mix longer, or go back one step. Some cats switch in a week; others need three or four weeks.
When you top up after scooping or refill the box, use the mix for the step you have reached.
Signs your cat accepts the new litter, and signs they do not
Going well: your cat walks in, digs, uses the box, covers, and walks out calmly, with the same number of visits as before.
Not going well:
- sniffing the box and walking away, or sitting on the edge instead of in the litter
- using the box but not digging or covering, or shaking the paws as they leave
- peeing or pooping just outside the box, or on a soft surface like a rug or bed
- using only the old box, or holding on and going less often
Best Friends notes that stressed cats can also hide, groom less, eat less, seem less interested in attention, or be quieter than usual. If you see these signs during a switch, slow down or go back to the old litter.
If your cat refuses the new litter
- Go back to the old litter. Clean up any accidents, put the familiar litter back, and let your cat settle for a week or two before trying again.
- Clean accidents with an enzyme cleaner. Battersea says to clean soiled spots as soon as possible so your cat does not go back to them, and suggests an enzymatic cleaner made for pet urine. See our best enzyme cleaner for pet urine guide, which covers cleaners such as Rocco & Roxie Stain & Odor Eliminator. Avoid bleach and strong-smelling cleaners near the box; Battersea says they can put cats off.
- Try a litter closer to the old one. Battersea suggests a softer litter when a cat avoids the tray. If you were moving from fine clay to large pellets, try a finer, unscented litter instead.
- Check the box, not only the litter. Battersea also suggests a bigger tray, taking the lid off a covered tray, and a quiet spot away from doors and windows. A tray should be at least 1.5 times your cat’s length from nose to the base of the tail.
- Never punish. Battersea warns that punishment or harsh methods can make toileting problems worse.
- See your vet if accidents go on. Battersea says any change in a cat’s toileting routine should be checked by a vet, and Best Friends says the vet is always the first step when a cat stops using the box.
Special cases
Kittens
Best Friends says non-clumping litter is safest for kittens under 16 weeks old. If you are moving a kitten to clumping litter as it grows, wait until then and use the same slow mix. For first-time training, see how to litter train a kitten.
Senior cats
Older cats can be slower to accept change. Keep the old litter on hand for longer, use a low-entry tray, which Battersea suggests for kittens and older cats, and ask your vet about any new accidents rather than putting them down to the litter.
More than one cat
Both Best Friends and Battersea suggest one box per cat plus one extra, and Best Friends adds one per floor. That extra box is the easiest place to offer the new litter. Watch every cat, not only the first to try it. See our best litter box for multiple cats guide.
Switching to pine, crystal or paper
Pellets and crystals feel very different from sand-like litter, so take the second box route and allow more time. Litters such as Feline Pine Original or Fresh Step Clean & Care Crystal are worth offering side by side before you mix anything. For a fine, unscented clumping option, our odor control guide covers World’s Best Cat Litter Multiple Cat Unscented and Dr. Elsey’s Ultra.
Switching to a self-cleaning box
Battersea says automated or self-cleaning trays can put some cats off because of their noise, movement or smell. Some need a specific litter, such as crystals. Change one thing at a time: get your cat used to the new litter in a normal box first, then bring in the new box. See our best automatic litter box guide.
Introducing a self-cleaning box? See how to get a cat to use an automatic litter box, from starting it switched off to turning on the cleaning cycle.
Living with an older cat? Our guide on how to set up your home for a senior cat covers low-entry litter trays, water on every floor, warm beds and steps to high spots.
FAQ
How do you transition a cat to a new litter?
Put out a second box with the new litter next to the old one. If your cat uses it, mix the new litter into the old box a little at a time until it is all new. Best Friends describes this method.
How long does it take a cat to get used to new litter?
Many cats take one to two weeks with a gradual mix. Wary cats, older cats and big changes in texture can take three or four weeks. Let your cat set the pace.
Can I switch cat litter all at once?
Some cats cope, but it is a risk. Battersea lists a different brand of litter among changes that can unsettle a cat, so a gradual switch is safer.
Why is my cat peeing outside the box after I changed litter?
Your cat may dislike the smell or feel of the new litter. Go back to the old one, clean the spot with an enzyme cleaner, and try again more slowly. If accidents go on, or your cat strains or passes blood, see your vet.
More on litter box care: how to deep clean a litter box and our cat litter and litter box buying guide.