Crystal cat litter (a.k.a. silica gel litter) is a relatively new invention in the long history of cat litter, but in two short decades it has earned a devoted following for its long lasting absorption, easy maintenance, and great odor control. So is it really better than clay litter? Does silica have any health concerns? In this article, we’ll explain what all the hoopla’s about and give you our picks for the best crystal cat litters on the market today.
Here at tuft + paw, we are cat experts. Over the last couple years, we've spent countless hours determining which litter features are most important to cats and cat parents alike. To compile this list, we consulted cat behaviorist Nicole Van Andel, veterinarian Megan Teiber, and hundreds of customer reviews to figure out which crystal litters offer the best performance.
soft texture, good odor control, absorbent, unscented, lightweight
expensive, dusty, mediocre tracking, some urine pooling
$24.51 for 7 lbs = $3.50/lb
What Is Crystal Cat Litter?
Crystal cat litter is a mineral-based litter made from granules of amorphous silica gel (NOT crystalline silica! More on that later). These small hard granules are extremely porous, making them very lightweight and super absorbent. When exposed to liquid, the porous “crystals” pull moisture inside their network of microscopic pores, trapping the liquid and any smelly compounds it carries. Gradually, the trapped water is allowed to evaporate and the smelly compounds remain stuck inside the crystals. And voila! That’s the secret behind crystal litter’s acclaimed odor control.
Crystal cat litter was first introduced in 1998 by brothers Dan and Russell Schlueter under the brand name Crystal Clear Litter Pearls, which soon after rebranded to Ultra Pearls. Clorox quickly launched its own competing crystal litter called Fresh Step, and these two brands have dominated the crystal cat litter market to this day (but that’s starting to change).
Crystal litter is not usually considered a natural or eco-friendly litter option. Silica is technically a naturally occurring mineral, but the environmental damage caused by silica mining and the fact that it's not biodegradable disqualify it from the "natural" category. However, it's still better than clay because it's non-toxic and lasts much longer.
If you don’t care about the nerdy details of silica gel, feel free to skip to the next section.
Let’s get it out of the way: yes, silica gel litter is made from the same material as those “DO NOT EAT” desiccant packets. While we definitely don’t recommend eating those packets (or crystal cat litter), silica gel is not toxic and does not pose any serious health problems for humans or cats.
Silica is also known by its chemical name silicon dioxide, and is harvested in the form of quartz crystals in open pit mines. To make silica gel, silica sand is heated with oxygen and water, which creates a network of tiny pores inside each silica granule. This process changes silica’s molecular structure from crystalline to amorphous.
Nerdy fun fact: silica gel is often described as being absorbent, but technically it does not absorb moisture (with a "b"). Instead, it adsorbs moisture (with a "d"). Adsorbent materials work by attracting liquids to their surface, while absorbent materials pull moisture into the material itself. That’s why silica gel doesn’t swell when sucking up moisture—it just pulls liquid into its tiny internal pores.
Is Silica Gel Dangerous for Cats?
No! Silica gel is totally safe for cats and humans. The dangerous type of silica is crystalline silica dust, which is found in clay cat litters. When inhaled over long periods of time, crystalline silica dust can cause a condition called silicosis, leading to chronic respiratory problems and even lung cancer. Silica gel dust, on the other hand, has an amorphous molecular structure and does not pose any serious health problems (other than being irritating to inhale).
How to Use Crystal Cat Litter
Using crystal cat litter is pretty straightforward and requires minimal maintenance. Just scoop the poops and stir the litter 1-2 times per day to help it absorb all the liquid waste. When crystal litter stops controlling odors, absorbing liquids, or looks yellow/beige, it’s time to change the litter entirely. At that point the crystals are likely saturated and will need to be replaced with fresh litter. Ideally, a box of crystal litter should last around 30 days for one cat.
Many cat parents like to use crystal cat litter with an automatic litter box. Its fine texture sifts easily and doesn’t clog the motor or rake system. Of course, it also works great with a traditional litter box setup.
Crystal cat litter should be kept away from wet and humid places like the bathroom. Silica gel absorbs water vapor from the air, so in humid conditions it won’t be able to absorb as much urine and urine won’t evaporate as quickly. Store opened crystal litter bags in dry, well-ventilated places and always keep the bags sealed tightly.
Reusing crystal litter is theoretically doable but we don't blame you if you'd rather not—cleaning it can be a tad stinky. If you really want to try reusing dirty crystal cat litter, follow these steps:
Mix it in a bucket with baking soda, vinegar and hot water. Let it sit for a few hours.
Drain and add cold water. Let it sit for several hours or overnight.
Rinse a few more times until all the color and smell is gone.
Silica gel is one of the most absorbent cat litter materials because of how porous the crystals are. It stays absorbent for a long time and does a great job of dehydrating poops, which in turn helps with odor control. Some crystal litters make the bold claim that they can absorb 40x their weight in liquid, but this is contradicted by the fact that silica gel can only hold 40% its weight in liquid at one time. We think what they mean is that the litter can absorb 40x its weight over the lifetime of the product.
Good Odor Control
Crystal cat litter is well-known for its impressive odor control. Silica gel essentially “traps” odors inside it by absorbing liquid waste, allowing water to evaporate, and keeping the stinky particles stuck inside its micropores. Speaking of odor, you can also check out our list of the best litters for odor control.
Low Dust (vs Clay)
Crystal cat litter is generally lower in dust than clay, but still dustier than some natural litters. Dust content differs from brand to brand, but whatever dust is present isn’t the harmful crystalline silica dust that clay litters produce. Veterinarian Megan Teiber considers crystal litter a good option for cats or owners with respiratory problems.
Easy to Clean
One of the main selling points of crystal cat litter is that it’s quite low maintenance. Users just have to scoop poops and give the litter a stir every day. It might not be any less work than scooping clumps, but many cat parents prefer it. If stirred diligently, crystal litter is easy to clean when it’s time to change out the litter box because it doesn’t leave any cemented clumps behind. Crystal litter is also an excellent fit for automatic litter boxes, which makes cleaning even easier.
Silica gel is a very light substance because of how porous it is. This means it can be sold in small, easy-to-handle bags that still last an impressively long time, much like tofu litter (in fact, we have an article that directly compares these two lightweight litter types: tofu litter vs crystal litter).
Resistant to Spoilage
Silica gel is an inorganic, non-biodegradable substance, so it’s not susceptible to mold like natural litters are. Furthermore, it creates a dry environment in the litter box that makes it hard for bacteria to grow.
Silica gel is totally non-toxic and safe for both humans and cats. Despite its name, crystal cat litter does not produce the harmful crystalline silica dust that clay litter does.
Drawbacks of Crystal Cat Litter
Silica is a mineral harvested through open pit mining, where it is sourced in the form of quartz. Open pit mines can be some of the largest industrial sites in the world, where massive amounts of earth are displaced to access the minerals underneath. Any habitat or vegetation that previously existed on the site is destroyed, and the surrounding landscape becomes vulnerable to erosion, water pollution, and extensive air and noise pollution.
Silica gel is not a biodegradable material, so it cannot be composted or flushed. It takes up landfill space and breaks down very slowly.
Crystal cat litters come with a hefty price tag when compared to clay, and even most natural litters. However, it can still provide great value for some households because of how long the litter lasts.
Crystal cat litter is basically just silica sand, so yes, it does track. How much depends on the crystal size and shape. Larger crystals track less, but can be uncomfortable for cats and humans to step on. A high-sided litter box and litter mat can help minimize the tracking of crystal litter.
Veterinarian Megan Teiber considers the biggest downside of crystal litter to be the unforgiving texture. Some cats may reject the litter box altogether if they find the crystal litter too rough for their sensitive paws. Fine crystal litters are more paw-friendly, but also track more.
Most crystal cat litters do not clump, and those that do usually do it poorly (spoiler: no clumping crystal litters made our list). This means urine stays in the litter box, so cat parents have to stay on top of stirring to keep the box smelling acceptable. Stirring vs scooping is more of a personal preference, but it’s something to keep in mind if you’re used to clumping litters. In general, some of the best non-clumping litters on the market are crystal litters.
Some drawbacks that are minor or brand specific include:
Dust content — crystal cat litter is made of a mineral, so it has the potential to be very dusty if the manufacturer doesn’t process it properly. Virtually every crystal litter will get dusty over time, because the crystals break down with use.
Popping noises — Some crystal litters make popping noises when wet. This seems to be something that certain silica gels do when exposed to liquids, but not when absorbing airborne moisture. Some cats might not like sound effects accompanying their pee breaks.
Added chemicals — Many crystal litters contain synthetic scents or colors.
Our Criteria for Choosing the Best Crystal Cat Litter
The following criteria were developed in consultation with veterinarian Megan Teiber and cat behaviorist Nicole Van Andel.
Tracking — How much litter ends up outside the litter box, and how far from the litter box it can get.
Dust — How dusty the litter is. This factor is very important for cats and people with respiratory issues and allergies.
Odor control — How well the litter neutralizes smells. Controlling urine smell is the key here, because no litter can truly neutralize the smell of solid waste. Keep in mind that odor control partially depends on individual cats and the strength of their urine odor.
Scent — Unscented is always preferable. Cats rely heavily on their sense of smell to interact with their surroundings, so strongly scented litter can be overwhelming.
Absorption — How much liquid the litter can absorb before becoming saturated. This is a crucial aspect of odor control.
Ease of cleaning — How well the litter coats solid waste and how much it sticks to the litter box.
Health & safety — The fewer additives the better. This includes scents, preservatives, and colors.
Ease of handling — How easy the litter is to transport, pour, and handle.
Price: $24 for 6 lbs = $4.00/lb Rating: 4.9/5 with 23,830 reviews on PrettyLitter Ingredients: silica gel crystals, color-changing compounds
Pretty Litter is the poster child for forward-thinking crystal cat litter. Its defining characteristic is that it changes color depending on the pH and blood content of your cat’s urine, which can help cat parents catch certain health problems early and save money on vet bills in the long run. However, Pretty Litter does have other great features too—users often praise its absorbency, how easy it is to clean, and how long it lasts. Reviews of its odor control are mostly positive, though there are a few bad reviews out there. Finally, we like Pretty Litter’s ability to coat and dehydrate solid waste, its soft texture, and the lack of added scents.
Pretty Litter says that you should scoop poops and stir the litter daily to make sure urine is entirely absorbed. According to the brand, 4 pounds should last an entire month if these suggestions are followed. Nevertheless, some reviewers found this wasn't always accurate for their cat; it really depends on how often your cat urinates and how strong their urine odor is.
As with many crystal litters, the most common complaint about Pretty Litter is that it’s pricey—at $4.00/lb, it’s one of the more expensive litters on the market. This polarizes users, with some feeling that it's not worth the price and others feeling they got what they paid for. There are cheaper options available but if your cat is elderly or has urinary issues, Pretty Litter might be worth considering. Lastly, Pretty Litter has manageable dust and tracking, but isn’t outstanding in those departments.
Price: $23.99 for 8 lbs = $3.00/lb on Chewy Rating: 4.4/5 with 487 Amazon reviews Ingredients: silica gel, hydrolyzed herbs
Dr. Elsey’s is a brand better known for clay litter, but they’ve also successfully entered the silica game with their Precious Cat Crystal Attract Litter. Formerly known as the Precious Cat Long Haired Crystal Litter, this formula has slightly larger crystals for reduced tracking. The crystals are smaller than Fresh Step’s (#4 on this list), so they’re more comfortable to step on but track slightly more. Dr. Elsey’s has included some dried herbs to attract cats to the litter box, but they don’t specify which herbs they use. The odor control and absorbency of both liquid and solid waste are widely liked by users. We also appreciate that it’s unscented and uncolored, so cat parents can more easily see if something’s wrong with their cat’s peeing habits.
The weaknesses of Dr. Elsey’s are run-of-the-mill for crystal litters: inconsistent dust content, easily scattered by digging cats, and the high price point. At the time of writing, we found this litter substantially marked up on Amazon ($3.76/lb), but at a lower price on Chewy ($3.00/lb). Several reviewers were frustrated by the apparent price gouging occurring on Amazon—something to keep in mind if you’re wanting to use this litter long term. Another factor to consider is that this litter’s absorbency and odor control don’t last quite as long as Fresh Step.
Note: Dr. Elsey’s also offers a Senior Crystal Litter formula with smaller crystals and a softer texture, and a Respiratory Relief formula with “stress-reducing herbal essences” to help cats with breathing problems.
Price: $14.64 for 5 lbs = $2.93/lb Rating: 4.1/5 with 12,243 Amazon reviews Ingredients: silica gel
Ultra Pet Micro Crystals was one of the first crystal cat litters on the market and it’s remained popular for nearly 25 years. Users were consistently wowed by the odor control, whether using an automatic litter box or stirring the old fashioned way. It’s also very cat-friendly thanks to the lack of added scents and its sand-like micro crystals. In fact, many cat parents found success with this soft litter after their cat had refused to use other brands with rougher textures. Ultra Pet is also the second cheapest litter on our list ($2.93/lb), so it’s a good first option to try out crystal litter.
The central drawback for Ultra Pet Micro Crystals is its dustiness. There are some accounts of users happy with the low dust content, but far more that were disappointed, even comparing it to clay. Given the small size of the crystals, tracking was an issue as well. Urine pooling was mentioned occasionally, but could have been a consequence of infrequent stirring.
Price: $38.84 for 16 lbs = $2.43/lb Rating: 4.6/5 with 11,250 Amazon reviews Ingredients: silica gel, fragrance, color
Fresh Step is a mainstay in the crystal cat litter game and it has legions of devoted fans for good reason. Fittingly, users love the odor control of Fresh Step, with many remarking it’s the best in that department of any litter they’ve ever used. It has fairly large crystals for reduced tracking and usually has a very low dust content (but this can vary from bag to bag). Fresh Step’s absorbency is another strength—it sucks up urine and dehydrates poops effectively. It also happens to be the most affordably priced litter on our list at $2.43/lb. Overall, Fresh Step provides great value and can significantly simplify the litter box cleaning experience.
However, Fresh Step does have a handful of cons. First of all, it has an added blue color and an added scent, though many users find the fragrance very mild. Another tradeoff is that the large crystals, despite reducing tracking, are quite uncomfortable to step on if they end up outside the litter box. If humans don’t like stepping on Fresh Step, cats likely don’t either. There also seems to be some product inconsistencies, with several reviews mentioning that recent bags were dustier than expected.
As with all crystal cat litter, stirring regularly is essential for urine absorption and odor control. A few Fresh Step reviews we found complained about urine residue/sludge (yuck!) in the litter box. Other reviews that explicitly mentioned stirring everyday did not have these problems.
Price: $24.51 for 7 lbs = $3.50/lb Amazon Rating: 4.1/5 with 3,719 Amazon reviews Ingredients: silica gel
Litter Pearls is one of the many brands owned by Ultra Pet, the originators of crystal cat litter. The main strength of Litter Pearls Micro Crystals is the soft texture of the smaller granules. There are virtually no reviews of cats rejecting this litter because of the texture. It also has very solid odor control when stirred regularly and does a great job of absorbing urine and “mummifying” solid waste. A few users had success mixing this litter with cheaper clumping clay litters, thereby improving odor control without sacrificing clumping, and keeping the price point reasonable. We also like that this litter is unscented.
A common complaint was that Litter Pearls Micro Crystals was much dustier than their “99.9% dust-free” claim suggests. A few users felt the dust was just as bad as clay, and it worsened over time as the litter was used. Comparisons to Fresh Step were common, including: worse tracking but less painful to step on, slightly worse odor control, and more prone to urine pooling. Finally, the price is quite high and has recently risen on Amazon ($3.50/lb).
good odor control
some urine pooling
Conclusion: Your Cat Knows Best
Ultimately, we feel that Pretty Litter offers the best all-around crystal litter experience, but honestly there’s not a ton of difference between the litters on this list. All five have solid odor control, absorbency, and are much lighter weight than clay. If tracking is your main concern, then the larger crystals of Fresh Step or Dr. Elsey’s Precious Cat are good options, but keep in mind the texture may not be very paw-friendly. The fine grain litters like Litter Pearls Micro Crystals and Ultra Pet Micro Crystals offer a much gentler texture, but dust and tracking is more of an issue. We’ll close, as we always do, with veterinarian Megan Teiber’s advice: “the best litter is the one your cat will use.”
Okay, one last thing. Crystal cat litter is a very convenient product, but here at tuft + paw we personally prefer litters made from sustainably harvested, biodegradable materials. That’s why developed our own tofu litter called Really Great Cat Litter. It’s low tracking, all natural, and even flushable! Check it out if that’s your thing, or you can take a look at some of our other educational resources below.