The Best Air Purifiers for 2025

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As wildfires rage and smoke fills the air, air purifiers are more important than ever. The best air purifiers can remove particulate matter (the main pollutant in wildfire smoke), bacteria, dust, industrial emissions, mold, odor, pet dander, pollen, viruses, and other harmful contaminants from the air. But not all air purifiers are equally effective, so we're here to help you find one that works and has the features you want. We've been reviewing smart air purifiers for more than a decade. The Dyson Big & Quiet BP03 is our top pick for its wide coverage range, long filter life, detailed air pollution data, and useful app and voice controls, but our list of the best air purifiers has options for all room sizes and budgets.

What Makes an Air Purifier Smart?

Most air purifiers (not just smart ones) have sensors that measure the density of various airborne pollutants such as nitrogen dioxide (NO2, a toxic gas from car exhausts and power plants), PM2.5 (particulate matter smaller than 2.5 microns in size, including industrial emissions and tobacco smoke), PM10 (particulate matter up to 10 microns, including dust, mold, and pollen), and VOC (volatile organic compounds, or potentially harmful gases from things like cleaning products and paint).

Smart air purifiers typically feature Wi-Fi radios that let them connect to a companion app that shows your home's air quality. Some apps offer graphs of your air quality over time. Dyson breaks it down by pollutant, showing charts for each one.

Most smart air purifiers feature an auto mode that automatically adjusts the fan speed based on the level of pollution detected. They also typically let you set up an air purifying schedule so the machine automatically turns on and off at specific times. Some models feature Alexa, Google Assistant, and Siri support, so you can control them with voice commands.

If a smart air purifier is out of your budget, consider the $69.99 Amazon Smart Air Quality Monitor. This monitor tracks airborne pollution levels around the clock. You can pair it with a traditional air purifier to save money.

Common Contaminants and Their Health Effects

Some sources of indoor air pollution are obvious, like cigarette smoke, household cleaning products, and pet dander. Others are less so.

The US Environmental Protection Agency (EPA) says that thousands of products—including air fresheners, dry-cleaned clothing, and office equipment like copiers and printers—emit VOCs that can lead to a long list of health effects ranging from headaches to cancer. Moreover, concentrations of VOCs are typically much higher indoors than outdoors.

Anything that causes smoke—such as cooking, burning candles or incense, or lighting up a fireplace—can lead to elevated concentrations of particulate matter. The EPA says PM10 and smaller can "get deep into your lungs" and, in some cases, your bloodstream. Inhalable particles, especially PM2.5, which is 30 times smaller than the average human hair, may pose a greater risk to those with heart and lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), congestive heart failure, and coronary artery disease. Most smart air purifiers detect PM10 and PM2.5, but some high-end models also report the density of PM1.0 (particulate matter 1 micron or smaller).

Humidifiers can help relieve cracked lips and dry skin, but if you’re not careful to use distilled water and clean them often, they can provide a fertile breeding ground for bacteria and mold, which is then pumped into your air. Gas stoves, especially when not properly vented, can emit unsafe levels of NO2, which can irritate the respiratory system and exacerbate or contribute to the development of asthma.

Another gas pollutant to worry about, especially if you're renovating or redecorating your home, is formaldehyde. This chemical comes from many household items, such as carpets, flooring, furniture, rugs, insulating materials, particleboard, plywood, paint, varnishes, and wallpapers. Long-term exposure to low levels of formaldehyde can cause skin, eye, nose, and throat irritation. Higher levels can cause some types of cancer.

Dyson says that formaldehyde is 500 times smaller than 0.1 microns, making it difficult to capture. Not all air purifiers can detect and break down formaldehyde, and this feature typically comes at a premium price, so that's something to consider while you shop. Check out our in-depth reviews to see which contaminants each model detects and captures.

In some cases, exposure to airborne pollutants might not cause immediate symptoms, but it can lead to serious health problems down the road. For this reason, the EPA says, "it is prudent to try to improve the indoor air quality in your home even if symptoms are not noticeable."

Buying an air purifier isn't the only way to improve your indoor air quality. Other steps you can take include eliminating the sources of your air pollution, opening a window (as long as the outdoor air quality is good), and regularly vacuuming and dusting surfaces.

HEPA vs. Ionic vs. Activated Carbon: Which Filtration Method Is Best?

The machines on this list combat airborne contaminants using High-Efficiency Particulate Air (HEPA) filters, activated carbon filters, ionic technology, and/or UV light.

HEPA air purifiers are the most popular. To comply with the current baseline standard, HEPA filters are tested and certified to remove at least 99.97% of dust, pollen, mold, bacteria, and any other airborne particles as small as 0.3 microns. There are different levels of HEPA filters, but in general, you want to make sure the model you buy meets the baseline standard (many that do have a "True HEPA" label) and stay away from those marketed as "HEPA-like," "HEPA-type," or "HEPA-style," which might not be as effective.

According to Wirecutter, a NASA study found that HEPA filters can actually capture almost 100% of particles as small as 0.01 microns (10 nanometers), well exceeding the baseline standard. To put that in perspective, COVID-19 is about 60 to 140 nanometers, H1N1 influenza is about 80 to 120 nanometers.

Meanwhile, activated carbon filters are filled with porous carbon, which traps gases such as NO2 and VOCs, as well as foul smells, from the air. Activated carbon filters are often combined with HEPA filters, which do not remove gases.

The Dyson Purifier Cool TP07 features a 360-degree filter with a HEPA layer that captures allergens, bacteria, mold spores, pollen, and other pollutants, and an activated carbon layer that removes gases and odors. It also doubles as an oscillating fan. The version that destroys formaldehyde, called the Purifier Cool Formaldehyde TP09, costs $100 more. Dyson says its latest air purifiers, including the TP07 and TP09, not only meet the baseline HEPA filter standard but are also fully sealed to the HEPA H13 standard, meaning they can remove 99.95% of particles down to 0.1 microns.

The only downside to HEPA and active carbon models is that the replacement filters can be costly (around $50 to $100) and wasteful.

Other models, like the Sharp FXJ80UW, combine HEPA, active carbon, and ionic technologies. Sharp's model features an ion-generating unit that creates positively and negatively charged ions using water and oxygen molecules in the air and disperses them throughout the room. The ions then actively attach to and break down airborne pollutants like bacteria, mold, and viruses before returning to the air as invisible water vapor. Sharp says the technology reduced 94% of E.coli bacteria, up to 87.7% of mold fungus, and 90.3% of MS2 virus in a closed laboratory over four hours.

The primary concern about ionic air purifiers is their possible production of ozone gas molecules, a lung irritant that can exacerbate asthma symptoms and cause a host of other health issues. The safety of ionic air purifiers came into question in the mid-2000s after it was revealed that the then-popular Sharper Image Ionic Breeze air purifier produced ozone (an issue that eventually bankrupted the company).

As the California Air Resources Board (CARB) warns, some ozone-producing devices are still marketed as air purifiers. The Clean Air Agency maintains a list of potentially hazardous models to avoid.

All models on our list that use ionic technology are EPA-compliant, CARB-certified, and considered safe to use in your home for extended periods of time.

The Best Smart Air Purifier for Large Rooms

Recommended for rooms up to 1,076 square feet, the Dyson Big+Quiet has the widest coverage area of any model on this list. As a much more affordable alternative, the Morento HY4866-WF has the same stated coverage area, but you'll have to change the filter much more often than with the Dyson model. As another top-rated alternative for large rooms, we also highly recommend the Rabbit Air A3 (1,070 square feet).

In my roughly 1,000-square-foot, single-level home, most of the smart air purifiers I've tested can detect elevated levels of air pollution from several rooms away. Sometimes, when I'm frying veggies in the kitchen, the Dyson TP07 from the other end of my house even detects cooking smoke and automatically kicks on.

Can Air Purifiers Really Reduce Allergies?

According to the EPA, it is a bit controversial whether air purifiers can truly reduce allergies caused by larger particulates such as pollen, dust, mold, and animal dander.

"Most of these particles are found where they settle on surfaces in the home, rather than in the air," the EPA says. "They cannot be removed by an air cleaner unless disturbed and re-suspended in the air."

Before turning to an air purifier for allergy relief, consider what type of allergies you have. Air purifiers may do a better job of capturing pet dander compared to other types of allergens. According to the American Lung Association, pet allergens "remain suspended in the air for a long time, much longer than allergens from cockroaches or dust mites." Dust mites, on the other hand, "cling to particles that are too heavy to remain in the air for long" and settle into things like pillows, bedding, and furniture "within minutes."

In my experience, air purifiers aren't an infallible cure for pet allergies, but they can certainly help. To combat dander from my dog, I usually keep at least one air purifier running 24/7. I find it particularly helpful to have one blowing clean air in my direction at night when my symptoms worsen.

Going forward, we'll continue to update this list as we review new models we deem worthy of inclusion. Check back often, and in the meantime, let us know in the comments if you want us to review any specific smart air purifiers.