How do I get cat pee smell out of carpet? What is the best enzymatic cleaner that actually works?

Getting cat pee out of a carpet requires more than just masking the smell—you have to break down the uric acid crystals in the urine, which reactivate and smell worse every time the humidity or temperature goes up.

Step-by-Step Cleaning Guide

1. Blot, Don't Rub (If Fresh): If the pee is still wet, blot up as much as possible using clean paper towels or an old towel. Stand on the towel to press down, but do not rub , which pushes the urine deeper into the carpet fibers and pad.
2. Skip the Wrong Cleaners: Never use steam cleaners, vinegar, ammonia, or regular household bleach on a cat urine stain. Heat sets the protein, and ammonia smells like urine to a cat, practically inviting them to pee there again.
3. Soak It Generously: Pour or spray your enzymatic cleaner liberally over the area. You need enough liquid so that it penetrates not just the carpet surface, but also the backing and the carpet pad underneath (where the pee actually pools).
4. Let the Enzymes "Dwell": This is where most people fail. Do not wipe it up right away. Cover the area loosely with an upturned laundry basket or plastic wrap (to keep it wet longer) and let it sit for at least 8 to 12 hours . Enzymes need time to actively eat away and digest the uric acid crystals.
5. Blot and Air Dry: Blot up the remaining moisture with dry towels. Let the area air dry completely. Do not walk on it while it's drying.

Highly Rated Enzymatic Cleaners That Actually Work

Widely considered a gold standard by pet owners; relies on activated bio-enzymatic bacteria to target both fresh and deep-set urine crystals.

Specifically formulated for pungent cat urine formulas with targeted enzymatic action.

A trusted, natural, bio-enzymatic choice that uses live enzyme cultures without harsh chemical fumes or overwhelming synthetic scents.

Uses a rapid molecular-and-enzymatic dual-action approach to instantly neutralize residual odors.

To help narrow down the best next step, let me know:

• Is the spot fresh or old/dried-in?
• Have you already tried cleaning it with other household products (like vinegar or baking soda)?

I can tell you whether you need a deep-soak treatment or if the carpet pad underneath might need specialized attention.

Yes—enzymatic cleaner is the right answer, especially for cat urine. The key is not just the product; you have to get enough cleaner deep into the carpet and pad to reach where the urine went.

My top picks

• Rocco & Roxie Professional Strength Stain & Odor Eliminator - $19.99 (Chewy)

My first choice: Rocco & Roxie Professional Strength. Current testing/reviews consistently put it near the top for stubborn pet urine, and it has the Carpet and Rug Institute's Seal of Approval.

• Nature's Miracle Urine Destroyer Plus for Cats - $37.49 (Chewy)

• MisterMax Anti-Icky-Poo - $43.95 (Chewy)

• Simple Solution Pet Urine Destroyer - $40.50 (Chewy)

• Rocco & Roxie: Best overall for carpet, particularly old/stubborn odor.

• Nature's Miracle Urine Destroyer Plus for Cats: My choice if you specifically want a cat-urine formulation and good availability/value.

• MisterMax Anti-Icky-Poo: Worth trying when you've already used several cleaners and the smell keeps coming back; it's the "nuclear option" I'd consider before replacing carpet/pad.

How to actually get the smell out

1. Find the entire contaminated area. If the spot isn't obvious, a UV/black light can help locate old urine.
2. Don't just mist it. Saturate the carpet enough that the enzymatic cleaner reaches the backing/pad where the urine went.
3. Let it dwell. For Rocco & Roxie, the guidance for deep odor is to allow substantial contact time—roughly 30–60 minutes or longer for deep contamination, rather than immediately wiping it up.
4. Blot/extract rather than scrub. A wet/dry vacuum or carpet extractor is particularly useful for pulling out the contaminated liquid.
5. Let it dry completely. This can take a day or more. Don't judge whether it worked while the carpet is still wet.
6. Repeat if necessary. Old cat urine can require multiple treatments because it may have penetrated into the pad or even the subfloor.

One important mistake to avoid

Don't use ammonia-based cleaners. Besides not solving the underlying urine residue, ammonia can resemble the smell of urine to cats and potentially encourage repeat marking.

Also skip simply covering the smell with fragrance. The whole point of an enzymatic product is to break down the organic material rather than perfume over it.

If the smell is really bad or returns every time the humidity rises, the urine is probably in the carpet pad/subfloor. In that situation, spraying the carpet surface repeatedly may never completely solve it—you need the enzyme solution to penetrate that lower layer, and occasionally the pad has to be replaced.

If you tell me whether the pee is fresh, days/weeks old, or a long-standing smell—and whether it's wall-to-wall carpet or an area rug, I can tell you exactly how I'd treat it and how much cleaner to use.

Getting cat pee smell out of a carpet requires breaking down the uric acid crystals in the urine, which normal soaps and vinegar just can't do. When cat urine dries, uric acid crystals form and remain dormant, but whenever humidity rises, those crystals reactivate and release that unmistakable ammonia smell.

Step-by-Step Guide to Removing Cat Pee Smell

1. Blot, Don't Rub: If the spot is fresh, press clean, dry paper towels or a microfiber cloth firmly onto the area to absorb as much liquid as possible. Rubbing will only push the urine deeper into the carpet fibers and padding.
2. Skip Harsh Chemicals (Initially): Avoid using steam cleaners, ammonia, vinegar, or store-bought conventional carpet shampoos before using an enzyme cleaner. Heat sets protein stains, and harsh chemicals can kill the active bacteria/enzymes needed to digest the urine.
3. Saturate Generously: Pour or spray your enzymatic cleaner so that it penetrates not just the carpet surface, but reaches deep down into the backing and the subfloor/padding. A general rule of thumb: the liquid cleaner needs to reach every single place the urine touched (use a UV blacklight if you need to map out old, hidden spots).
4. Let It Dwell (Crucial Step): Do not wipe it up immediately. Enzymatic cleaners need time to do biological "work." Let the area sit wet for 10 to 15 minutes minimum, or up to 8 to 10 hours for deep, set-in messes (check the product label for specific dwell times). Cover it loosely with a plastic sheet or inverted laundry basket to keep it wet longer and prevent pets from stepping in it.
5. Blot Dry: Press dry towels onto the area to extract the excess liquid.
6. Air Dry Completely: Let it dry naturally. Do not use a hot iron or heated blow dryer. Once completely dry, the chemical breakdown is finished, and the smell should be permanently gone.

The Best Enzymatic Cleaners That Actually Work

Widely regarded as a gold standard by pet owners and top reviewers. It uses professional-strength enzymatic bacteria that actively feed on ammonia crystals and organic residue until the source is completely eradicated.

Specifically formulated for the heavy-duty composition of feline urine. It targets extreme, old, and set-in yellowing stains and deeply embedded pheromones so cats aren't tempted to re-mark the spot.

A favorite for eco-conscious households. It relies on live, safe enzyme-producing cultures that naturally break down organic waste, pet accidents, and tough smells without harsh artificial fragrances.

Uses a bio-enzymatic dual-action formula that rapidly targets the molecular source of severe odors rather than just masking them.

If the pee has soaked deeply into the carpet padding or subfloor , surface cleaning might not be enough. Do you know if this is a fresh accident or an old, recurring spot ? I can give you advice on how to treat the padding if the smell persists.

Yes. For cat pee specifically, I’d buy Rocco & Roxie Professional Strength Stain & Odor Eliminator. Current 2026 comparisons consistently put it among the strongest options for set-in urine, and it has the Carpet and Rug Institute’s approval for carpet use.

• Rocco & Roxie Supply Co. Professional Strength Pet Stain & Odor Eliminator - $19.99 (Chewy)

How to actually get the smell out

The biggest mistake is spraying a little cleaner on the surface. Cat urine can soak through the carpet into the backing and pad, so the cleaner has to reach as deeply as the urine did.

1. Find the entire contaminated area. If you have a UV/black light, use it at night; urine spots can extend considerably beyond what you can smell or see.
2. Don't use vinegar, bleach, ammonia, or regular carpet shampoo first. You want the enzymatic product to have direct access to the urine residue.
3. Saturate the carpet thoroughly with Rocco & Roxie. Don't merely mist it. For an old accident, you want enough liquid to penetrate toward the carpet pad.
4. Let it dwell. Rocco & Roxie's directions call for roughly 30–60 minutes for significant contamination; deeper/older contamination may need another treatment.
5. Blot/extract the excess, then let it air-dry completely. Don't judge the result while it's wet.
6. Repeat if necessary. Old cat urine can require two or three treatments. One real-world long-term test found that fresh urine came out completely while some old dried spots required multiple applications.

If the smell keeps coming back

That's an important clue: the urine is probably in the carpet pad or even the subfloor, rather than just the carpet fibers. Enzyme cleaner can't solve a problem it doesn't reach.

If it's a large/old spot, I'd actually pull up the carpet at the affected area and treat the carpet backing and pad separately. If the pad is saturated with years of urine, replacing that section of pad is often much more effective than repeatedly spraying the carpet.

My picks

• Rocco & Roxie Professional Strength Stain & Odor Eliminator - $19.99 (Chewy)

• Nature's Miracle Urine Destroyer Plus for Cats - $37.49 (Chewy)

• Urine Off Cat & Kitten Formula - $15.99 (Chewy)

• Simple Solution Extreme Cat Stain & Odor Remover - $16.71 (Chewy)

• 🥇 Best overall: Rocco & Roxie — my first choice for stubborn carpet odor. Strong track record on old urine and good carpet-safety credentials.

• 🥈 Best cat-specific alternative: Nature's Miracle Urine Destroyer Plus for Cats — specifically formulated for cat urine and yellow/sticky urine residue.

• 🥉 Another good option: Urine Off Cat & Kitten — specifically designed around cat urine and uses bio-enzymatic technology.

• Budget option: Simple Solution Extreme Cat — specifically formulated for cat urine and has good user ratings.

One important tip: If you tell me whether the pee is fresh or old, how big the affected area is, and whether it's wall-to-wall carpet or a removable rug, I can tell you exactly how much cleaner to use and whether you need to treat the pad underneath.

Cat urine is uniquely brutal because it contains urea, urobilin, creatinine, and concentrated uric acid crystals. Regular household cleaners, steam cleaners, or vinegar will temporarily mask the smell or break down the easy proteins, but uric acid crystals remain dormant and reactivate—releasing that unmistakable ammonia smell—whenever the humidity or temperature rises.

Only a true bio-enzymatic cleaner with live bacteria/enzymes can chemically digest those crystals down to an odorless state.

The Best Enzymatic Cleaners That Actually Work

Pet owners and cleaning experts generally agree that standard grocery-store sprays are often too diluted. These top-performing formulas consistently get the best real-world results:

Highly rated by pet owners for deep-set and severe odors, it uses enzymatic bacteria that actively seek out and consume ammonia crystals and organic residue.

Specifically formulated for heavy-duty cat messes . Make sure you grab the version explicitly labeled for cats or Urine Destroyer , as their basic multi-pet formulas are sometimes less effective on concentrated feline uric acid.

A professional-grade, slightly industrial product favored by vets and rescue shelters. It works brilliantly on deep-set carpet padding, though it requires patience and a thorough drenching.

Features a 3X Pro-Bacteria formula designed explicitly to break down the heavy proteins and urea in cat pee.

Step-by-Step: How to Get It Out of the Carpet (and Padding)

If you don't treat the carpet padding underneath, the smell will remain. Follow this exact process:

1. Blot, Don't Rub : If the spot is fresh, press clean paper towels or an old microfiber cloth firmly onto the area to soak up as much liquid as possible. Do not scrub, or you will fray the carpet fibers and push the urine deeper.
2. Drench the Carpet (Go Deeper Than You Think) : Pour or spray your enzymatic cleaner generously over the spot. It must reach the carpet backing and the subfloor/padding where the uric acid crystals actually live. If you only wet the surface fibers, it won't work.
3. Respect the "Dwell Time" : This is where most people fail. Enzymes need time to "eat" the organic material. Read the bottle, but generally, you need to let it sit wet for at least 15 to 30 minutes—and for severe or old stains, cover the wet spot with a piece of plastic wrap to slow down evaporation. Leaving it trapped under plastic for 24 hours lets the bacteria actively digest the deep crystals.
4. Blot and Air Dry : Remove the plastic, take dry towels, and step on them over the area to press out the excess liquid. Let it air dry completely. Do not use a hot steam cleaner or a hot iron to dry it, as heat will permanently bind the remaining urine proteins to the carpet fibers.
5. Vacuum : Once the area is 100% bone-dry, vacuum it thoroughly.
   (Optional Pro-Tip: If a faint shadow of the smell remains after a full drying cycle, apply a layer of baking soda over the dry spot, let it sit for a few hours, and vacuum it up to draw out any lingering micro-residues.)

To help tailor this advice, is the accident fresh or dried/old , and roughly how large is the affected area?

Yes — cat pee is one of those odors where the cleaning technique matters as much as the product. If the urine reached the carpet pad, a quick spray on the surface usually won't solve it.

My top pick: Rocco & Roxie Professional Strength

Rocco & Roxie Supply Co. Professional Strength Pet Stain & Odor Eliminator

$19.99

I'd choose Rocco & Roxie Professional Strength Stain & Odor Eliminator for stubborn cat urine in carpet. It's bio-enzymatic, is certified by the Carpet and Rug Institute for carpet use, and its instructions specifically tell you to saturate deeply enough to reach the underlying pad for serious odors.

A recent independent cleaning-lab comparison also found it effective on difficult pet stains and odors.

If you want a cat-specific alternative

Nature's Miracle Urine Destroyer Plus for Cats

$37.49

Nature's Miracle Urine Destroyer Plus for Cats is my second choice and is specifically formulated for cat urine. The manufacturer says its bacteria-based enzymatic formula targets the urine and the sticky residue it leaves behind.

The trick that actually makes enzyme cleaners work

1. Don't use bleach, ammonia, or regular carpet cleaner first. Ammonia in particular can make urine-marking problems worse.
2. Blot/extract as much urine as possible.
3. Soak the affected carpet with the enzyme cleaner. Don't just mist the surface. If the urine got into the pad, the cleaner needs to get there too.
4. For an old/deep odor, keep it wet for at least an hour. Rocco & Roxie's directions specifically recommend penetrating the carpet and pad and allowing it to sit at least an hour; older contamination may require repeat treatment.
5. Put a folded towel over the area and weight it down to wick the cleaner and dissolved urine back out of the pad.
6. Let it air-dry completely. Don't use heat or steam while you're trying to enzymatically break down the urine.
7. Once completely dry, smell it. If you can still smell urine, repeat the treatment.

Important: If the smell comes back every time the room gets humid, or you can smell it from several feet away despite repeated treatment, the urine may have soaked through into the carpet pad or subfloor. At that point, surface cleaning won't necessarily fix it; the pad may need to be treated/replaced and the subfloor sealed.

If you tell me whether the pee is fresh, old/set-in, or from a cat that's been repeatedly using the same spot, I can tell you exactly how I'd tackle it—including how much cleaner to use and whether I'd pull up the carpet.

Yes — cat pee smell can usually be removed from carpet, but the trick is getting the enzymatic cleaner all the way through the carpet and into the pad, not just spraying the surface.

My top pick: Rocco & Roxie

Rocco & Roxie Supply Co. Professional Strength Pet Stain & Odor Eliminator

$19.99

I’d choose Rocco & Roxie Professional Strength for carpet. It uses a bio-enzymatic formula, is carpet-safe/CRI certified, and its own directions specifically say that for deep odors you need enough product to penetrate the carpet and underlying pad.

There is also some unusually useful independent testing here: a carpet-cleaning research database found both Rocco & Roxie and Nature's Miracle effective at reducing cat-urine odor in carpet, with Nature's Miracle showing particularly good persistence overnight.

If the smell is really bad or old

I'd consider Nature's Miracle Urine Destroyer Plus for Cats:

Nature's Miracle Cat Urine Destroyer Plus

$37.49

Nature's Miracle specifically instructs you to saturate the carpet, and for severe odors says you may need to lift the carpet and treat the pad/floor underneath. That's important because dried cat urine can penetrate surprisingly deeply.

For very stubborn/repeated urine contamination, Mister Max Anti-Icky-Poo is another one I'd put on the shortlist:

Mister Max Anti-Icky-Poo Unscented

$43.95

How I'd actually clean the carpet

1. Find the entire contaminated area. A UV/black light can be extremely helpful for old urine spots.
2. Don't use bleach, ammonia, or regular carpet shampoo first. In particular, ammonia-based cleaners can be counterproductive with cat urine.
3. Thoroughly saturate the urine area with enzyme cleaner. Don't just mist the top fibers. You want it to reach approximately as deeply as the urine did.
4. Let it dwell. For Rocco & Roxie, their instructions recommend at least an hour for deep odor problems; older contamination may need repeated treatment.
5. Cover with a damp towel for stubborn areas and put something heavy on top. This helps keep the treatment in contact with the carpet/pad instead of evaporating immediately.
6. Let it completely air-dry. Don't judge the result while it's wet.
7. Repeat if necessary. Old cat urine can require several treatments.
8. Only then shampoo/extract the carpet, if needed.

The biggest mistake is using too little cleaner. If a cat peed through the carpet into the pad, spraying the surface until it's merely damp won't solve the odor.

If you tell me whether the pee is fresh or old, roughly how big the affected area is, and whether the carpet is wall-to-wall or a removable rug, I can tell you exactly how much cleaner I'd use and whether you probably need to treat/replace the pad.

Cat urine is notoriously difficult to remove because it contains urea, urobilin/urobilinogen, and uric acid crystals. Regular cleaners or vinegar might mask the smell temporarily, but uric acid binds tightly to carpet fibers and padding, crystallizing as it dries and reactivating whenever the humidity or room temperature rises.

To eliminate the smell permanently, you must break down those uric acid crystals at a molecular level using a specialized bio-enzymatic cleaner.

The Best Enzymatic Cleaners That Actually Work

Pet owners and professional cleaners consistently rank a few heavy-hitting options at the top for performance:

Widely considered a gold standard by pet parents. It uses professional-grade enzymatic bacteria that target both the stain and the pungent ammonia/uric acid components without leaving a sticky residue.

A pro-grade, live-bacteria enzyme formula heavily favored by rescue workers and veterinarians. It comes in an unscented version, which is ideal if you are sensitive to heavy perfumes or if strong fragrances trigger your cat to re-mark the spot.

Readily available and affordable. Just ensure you buy the cat-specific formula (which targets concentrated feline urine chemistry) rather than the generic or dog versions.

Highly concentrated bio-enzymatic formula that tackles deep-set, old, or repeated accidents that standard pet store sprays fail to lift.

Step-by-Step Guide to Getting the Smell Out

Even the best enzyme cleaner will fail if it doesn't make physical contact with every layer the urine touched. Cat pee spreads outward and downward, meaning a small surface spot on top of the carpet is usually 3 to 4 times larger on the carpet pad and subfloor below.

1. Locate the exact boundaries : Use a Vansky UV Blacklight flashlight Go to product viewer dialog for this item. in a dark room to outline every dried splatter or ring of the stain.
2. Blot (do not scrub) : If the pee is fresh, use clean white paper towels or a microfiber cloth to press down and absorb as much liquid as possible. Do not scrub, as it frays the carpet fibers.
3. Skip the harsh household chemicals : Avoid using bleach, ammonia, vinegar, or steam cleaners before applying enzymes. Vinegar changes the pH balance and can neutralize the live bacteria, while heat from steam cleaners or carpet shampooers will literally cook the protein into the carpet fibers, locking the smell in forever.
4. Drench the area : Pour or heavily spray your chosen enzymatic cleaner so that it completely saturates the carpet, passes through the backing, and reaches the carpet pad . For deep or old stains, you may need an ounce or two per square inch.
5. Give it dwell time (Crucial) : Do not wipe it up right away. The enzymes need time to digest the uric acid crystals. Follow the product label, but generally, you should cover the wet spot loosely with a piece of plastic wrap (this slows down evaporation) and let it sit for 24 to 48 hours.
6. Air dry completely : Remove the plastic and let the area air dry naturally. Do not use a hot iron or heated blow dryer. Once completely dry, vacuum the area. If a faint smell returns on a humid day, it means the enzyme didn't reach the deepest part of the pad—repeat the drenching process.

If you'd like, let me know:

• Is the accident fresh or dried/old?
• Have you already applied other cleaners (like vinegar or carpet shampoo) to the spot?

I can adjust these steps if the urine has already penetrated down to the subfloor!

Cat urine is uniquely brutal because it contains urea, urobilin/urobilinogen, creatinine, and uric acid crystals. Regular cleaners, vinegar, baking soda, or steam cleaners only mask the smell or lock the uric acid crystals deeper into the carpet fibers and padding . When the humidity changes or the heater kicks on, those crystals re-hydrate and the smell comes roaring back.

Only live enzymatic/bacteria formulas break down the uric acid into odorless, water-soluble components.

The Best Enzymatic Cleaners That Actually Work

Widely considered a community and expert favorite for carpets and rugs . It relies on professional-grade enzymatic bacteria that target the core of the urine crystal. Note: It does have a distinct perfumed scent while wet, but it neutralizes the urine completely once dry.

A cult-favorite professional and pro-grade bio-enzymatic spray. The major selling point here is that they offer an unscented version , making it the top pick for anyone who is sensitive to heavy perfumes or worries that strong chemical scents will irritate their pets.

Highly rated for deep-set, severe, or multi-year old urine smells. It is super concentrated and relies on heavy-duty bio-enzymatic action to digest the organic waste.

Readily available and reliable, though make sure to buy the Cat-specific formulas (which target feline uric acid specifically) rather than the generic or dog ones.

Step-by-Step Guide to Getting the Smell Out

If you just spray and quickly wipe, you will fail. You have to treat the subsurface layers (the carpet backing and the foam pad below).

1. Blot (Do Not Rub): If the pee is fresh, press down hard with dry paper towels or old rags to extract as much liquid as humanly possible. Stand on the towels. Do not scrub, or you will fray the carpet fibers.
2. Soak the Area (Generously): Pour or heavily spray your chosen enzymatic cleaner directly onto the spot. You must use enough liquid so that it penetrates past the carpet fibers and reaches the carpet backing and pad where the urine pooled.
3. The Golden Rule—Let It Air Dry: This is where most people mess up. Do not blot it up right away. Cover the wet spot loosely with a piece of plastic (like an inverted plastic container or a sheet of plastic wrap) to slow down evaporation. This keeps the bacteria wet and "eating" the uric acid for hours. Let it sit for 12 to 24 hours.
4. Remove the Plastic and Let It Finish Drying: Take the plastic off and let the carpet dry completely on its own. Do not use a hot steam cleaner or a hair dryer —heat will cook and permanently set the remaining protein bonds.
5. Extract/Vacuum: Once it is bone dry, if there is any crunchiness or residue from the cleaner, vacuum it thoroughly or use a clean, damp cloth with cool water to lightly rinse the surface fibers.

To give you the most tailored advice, tell me:

• Is the accident fresh or completely dried/old?
• Have you already applied any other household cleaners (like vinegar, bleach, or standard carpet shampoo) to the spot?

Yes — cat pee is one of those odors where the technique matters almost as much as the product. If the urine has gotten into the carpet pad, spraying the surface usually won't be enough.

🏆 My pick: Rocco & Roxie

Rocco & Roxie Professional Strength Stain & Odor Eliminator

$19.99

For carpet, Rocco & Roxie Professional Strength would be my first choice. Current reviews and comparisons consistently put it among the strongest options for urine odors, and it's specifically formulated as a bio-enzymatic cleaner for organic stains and odors.

If you want something specifically formulated for cats:

Nature's Miracle Urine Destroyer Plus for Cats

$37.49

Nature's Miracle is an excellent alternative, particularly the Urine Destroyer Plus for Cats. It is bacteria/enzyme-based and specifically targets cat urine and the sticky residue left behind.

The important part: saturate, don't just spray

For a urine spot on carpet:

1. Find the entire affected area. A UV/black light can be very useful because the visible stain is often much smaller than the actual urine contamination.
2. Don't use bleach, ammonia, or a steam cleaner first. You don't want to interfere with the enzymatic treatment, and heat isn't your friend here.
3. Soak the carpet with the enzyme cleaner. Really soak it. The cleaner needs to reach wherever the urine went — including the carpet backing/pad.
4. Let it dwell. Follow the product's directions; for an old/deep accident, giving the enzymes substantial contact time is important.
5. Blot/extract rather than aggressively scrubbing. A wet/dry vacuum is particularly useful for pulling out the contaminated liquid afterward.
6. Let it dry completely. Don't judge the result while it's wet.
7. Repeat if you can still smell urine. Deeply contaminated carpet frequently requires multiple treatments. Real-world reports also emphasize that urine in the pad may require considerably more product than a superficial spot.

If the smell keeps coming back...

That's the big clue that the urine is in the padding or subfloor, rather than just the carpet fibers. In that situation, you can use gallons of enzyme cleaner on the surface and still get a urine smell whenever humidity rises.

For a serious/repeated accident, I'd actually consider Anti Icky Poo as the next product to try; it's specifically recommended for severe/repeat urine contamination.

Bottom line:
Rocco & Roxie → best overall first try.
Nature's Miracle Urine Destroyer Plus for Cats → best cat-specific choice.
Anti Icky Poo → my escalation choice when you've already tried cleaners and the smell keeps returning.

If you tell me whether this is a fresh pee spot, an old stain, or a whole room that smells like cat urine, I can give you the exact procedure I'd use—including how much cleaner to use and whether you need to treat the pad/subfloor.