More than 35,000 reviewers give this air purifier five stars, and many report better breathing and alleviated allergy symptoms. One user from Napa, California, bought this after a forest fire and writes, “This air purifier has made breathing noticeably easier in our home, and the air smells much cleaner, especially with the ultraviolet light turned on.” Many customers chalk up how well and quickly this purifier works to the True HEPA filter. “I bought this model specifically because it uses ‘True HEPA’ filtration, which filters out the smaller smoke particles that can get into your bloodstream,” one writes. Another reviewer warns, “The replacement True HEPA filters are a bit pricey at around $28 last I checked, but they last about six months, give or take.”

Beyond collecting dust, this purifier gets lots of praise for eliminating odors. “The smell of the litter box was the primary reason I purchased this air purifier,” one reviewer writes. “After using this air cleaner regularly for about two years, I can confidently say that it effectively and completely removes the smell of the litter box, helps control the amount of hair that floats around the room, and generally does a very good job keeping dust from accumulating in the room.”

This is the same brand as our best-rated pick, but it’s a much smaller version for kitchens, bathrooms, kids’ rooms, and right above litter boxes. One customer says it cut down the smell of his cats litter box “by 95%.” Another reviewer “basically had to clean the kitchen every single day to deal with lingering smells,” but she has no issues with odor now, thanks to this purifier. Because this pluggable purifier is so small, reviewers like that they can put it in a very targeted area to eliminate smells, but one customer warns that “its light is pretty bright (nightlight bright),” so you might not want to put it in a place that requires total darkness. And one more reviewer reports that it actually covers a larger space than many might think. She explains that the people who live downstairs from his apartment smoke, which makes their kitchen “reek of cigarettes,” but after she got this to clear up the “old, dirty ashtray” smell, she writes, “I honestly didn’t expect much from this tiny thing. I plugged it in right next to the garbage can and the next morning there was no smell! I’m amazed.”

More than 80 percent of this air purifier’s over 20,000 reviewers give it five stars, and many call out how well it detects and removes odors. “My teenage daughter and I were sitting on the couch when she suddenly let loose with a fart,” one writes. “Maybe 1, 2, seconds later the purifier went from blue to orange. We about died laughing! It filtered that fart for about 10 minutes or so, then went back to blue.” Many users think the Winix PlasmaWave feature is what helps the most with odors. “The PlasmaWave air ionizer also works great and neutralizes odors that might get thru the other filters and virtually eliminates cooking odors and have found it to work on odors that are produced when a kerosene heater is first lit,” one user says. “This stopped the fumes from going past the room the heater was in and in short order eliminated the smell from that room.”

“I’m geeking out on the air I’m breathing,” one reviewer writes. “Is it weird that I don’t ever want to leave the house now? I just want to stay inside and breathe the GOOD air! No more cat box smell! No more old house smell! The sun used to come through the window in the evening and light up all the particles in the air. Not anymore! I live in an urban area but I breathe like I’m in the countryside.” And they’re not the only reviewer impressed by how clean their air feels after using this purifier. One often-cited feature, mentioned by over 200 reviewers, is the automatic function. “If I sweep the room with a broom or do anything else to kick up some dust, the unit automatically increases the fan speed to start removing the dust,” one reviewer writes, while another says, “It will stay on the lowest setting most of the time, but it does sense particulates and will often speed up the fan when we are cooking, spray [an] air freshener or if the dogs come in and shake dust around.”

Over 1,600 reviewers were impressed with this small-but-mighty tabletop air purifier, praising its ability to cut out cooking smells and pet odors. With its slim design, many say it’s also perfectly suited to sit atop desks or nightstands. “Nice small air cleaner that packs a real punch!” writes one reviewer. “I have one in each of our bedrooms. They are small, compact and do a great job cleaning the air.” Another reviewer who is a prolific vaper purchased this to “help reduce the amount of vapor clouds in our family room,” and says it’s “been doing a phenomenal job … I put [it] on the end table next to where I sit and exhale my clouds in the direction of this purifier and it helps to eliminate about 90% of the vapor clouds.” A third reviewer says their wife prefers it to “the big ‘whole room’ purifiers as she can keep one on her desk and one on her nightstand … The oldest one we have has been going, almost nonstop for 4 years. Very much worth the money!”

Lots of customers lament that leaving their air purifier on during the day raises their energy bill. But this Blueair purifier is Energy Star compliant, so it takes up less energy than other purifiers of the same size. “I leave it at the lowest setting throughout the day while I’m at work and [do] not feel too bad about it since it’s Energy Star compliant,” says one customer. And it’s quiet enough to keep in his bedroom, which is especially nice as he’s getting ready for bed. “You can tell the air is cleaner for a better night’s sleep.” Another customer runs hers throughout the day and hasn’t yet “seen a difference in the energy bill,” so she plans to keep running it continually, especially since she thinks “the air is definitely cleaner” when she does. “I barely need to dust anymore.” This one is a “bit pricey,” according to her, but she swears it’s “well worth it.”

This is basically the same air purifier as our energy-efficient pick, but it’s much smaller, so customers buying this were less concerned with energy efficiency. Instead, the carbon filters were the standout feature for customers with this one, because they effectively remove odors caused by smoke, pets, cooking, and more from rooms. One customer explains that, unlike regular filters, these carbon ones “remove ultrafine germs, particles, and odor” that other filters can miss. That’s, at least, been his experience: He’s tried many purifiers before and personally thinks this one is “the best designed air purifier” because “it really makes the air smell fresh.” One mom bought this for her daughter’s dorm room, and after letting it run for an hour, “Her room smelled a lot better right away from the carbon filter on the inside.” And aside from how well it works, many reviewers think it’s attractive looking.

Nearly a third of reviewers comment on the filters in this air purifier, and many praise them for being cheap to replace. “The cost of operation is one of the lowest of any purifier,” one reviewer writes. “A generic set of filters cost $47 here on Amazon and lasts 2 years.” And not only are they inexpensive, they’re also “so easy to clean or replace,” another reviewer writes. One word of warning that’s repeated by dozens of reviewers: “Remember to open it and take the plastic wrapping off the filters BEFORE turning it on,” one says. But if you do operate it properly, it’ll work well: “While I haven’t owned it long enough to notice a reduction in dust (especially since I dust about 4 times a week anyways), I can say that it clears up smells wonderfully. Homemade shrimp pad Thai, accidental Febreze overdoses, that blown out candle smoke smell, the after the dog park smell… All of it cleared out of the room in about five minutes.”