Best Air Purifier of 2024 - CNET

Article updated on October 9, 2024 at 10:00 AM PDT

We tested numerous air purifiers so you don’t have to. Here are the best ones to buy right now to ensure the air in your home is always as clean and safe as can be.

CNET’s expert staff reviews and rates dozens of new products and services each month, building on more than a quarter century of expertise.

CNET’s expert staff reviews and rates dozens of new products and services each month, building on more than a quarter century of expertise.

It's more important than ever to consider air purifiers a commonplace household product. Our planet's dependence on fossil fuels may be the driving force behind climate change, but it isn't just temperature we need to worry about. According to the US Environmental Protection Agency, climate change also affects our air quality and the frequency of natural disasters like hurricanes and wildfires.

While air purifiers can offer relief to those with allergies or respiratory conditions, experts recommend air purifiers for anyone. "The most important air pollutants are particular matter," says Jie Zhao, head of Delos Labs. This can occur in the form of smoke, dust, mold, allergens and so on. "I would recommend an air purifier to anyone even if you're just cooking at home."

Our state-of-the-art testing lab put dozens of popular air purifier models to the test to see which ones are the best at cleaning your air.

CNET's pick for best overall air purifier goes to the Blueair Blue Pure 311i Max. During lab testing, Blueair outperformed the competition clearing smoke and particles from the air faster and more effectively in our controlled testing chamber. Its versatility, low energy draw and relatively low noise level while running even on the highest setting, combined with its median price, made the Blueair an easy choice for the best overall air purifier.

In terms of smoke, seasonal allergens and dust, an important consideration in buying an air purifier is whether it has an automatic mode. Certainair particles do not remain consistent throughout the year or even throughout the day. “Auto-mode purifiers can automatically ramp up the speed when the pollution is higher,” says Zhao, which ensures they perform efficiently given real-time conditions and don’t waste energy when more power isn’t needed.

Air purifiers such as the BlueAir Blue Pure 311i Max with automatic mode respond to the actual air quality, and adjust the speed accordingly.

In addition to its automatic setting, BlueAir’s Blue Pure 311i Max was the top finisher at both low and high fan settings, bringing the particulate count down to pre-smoke levels in 6.6 and 2 minutes, respectively. On top of that, the Blue Pure 311i Max was the second most energy-efficient unit for its capacity and surprisingly quiet too, reaching only 46.1 decibels when running at its highest fan setting -- a full 9 decibels lower than the loudest model among those we tested.

The Blue Pure 311i Max also has voice controls and comes equipped with a five-color air quality indicator and a pollution-detecting particle sensor. Download the BlueAir App and you’ll be able to track air quality in your home in real time, control the air purifier remotely and even track filter usage so that you can order a new one when the time comes. It’s a simple, well-designed air purifier that performs exceptionally well, both in terms of energy usage and particle removal.

While a HEPA filter is an industry standard for air purification systems, an additional measure, a UV-C light, is especially equipped to handle pathogens such as viruses, bacteria and mold, and stop them from multiplying. “The best way to destroy pathogens is just to expose them to sunlight,” says Shahir Masri, associate specialist in air pollution exposure, assessment and epidemiology at UC Irvine Joe C. Wen School of Population & Public Health. “Air purifiers with a little UV light in there will do one extra task for you,” he said.

“If you're specifically concerned about infectious diseases, that's what that's going to be for,” he adds. “It's a biology killer.”

The Germ Guardian AC4300 had medium air-clearing performance among the air purifiers we tested, clearing 612 square feet in about an hour, with a median CADR (Clean Air Delivery Rate) between 99 and 116 depending on the particulate matter in question. It is suitable primarily for small spaces, with a slightly higher energy draw than those of a similar volume, but a lower running noise level. For those whose primary concern are pathogens such as viruses and bacteria, however, this is an effective model with a relatively small footprint and a modest price tag.

Size: 9x7x22 inchesRoom capacity: up to 153 square feetFilter type: HEPA filter with added antimicrobial, Activated charcoal, and UV-C lightReplacement filter cost: $35

The Coway Airmega 400s is among the largest and most powerful air purifiers on the market, with a hefty price tag to match, but it is an excellent option to consider for larger, open spaces. Its sophisticated four layers of filtering can handle particulate matter as microscopic as .1 micron in size, has among the highest CADR of any available models, between 325 and 400 depending on the particulate matter, and it can clear a whopping 3,100 square feet of space in about an hour.

Its functionality and features are on par with the Blueair Blue Pure 311i Max above, including an automatic mode that aids with particles such as smoke and seasonal allergens without running on high continuously. Its footprint, energy draw and price are all a more serious commitment, but it’s still a good value considering its expansive capabilities. For your money, you’re also getting all the bells and whistles: Wi-Fi capability allowing for voice or app control; smart, sleep and eco settings; real-time air quality monitoring.

While different kinds of particulate matter are indistinguishable to the air purifier itself, according to the experts we spoke to, an important consideration for particles such as pet dander is energy draw, since that type of pollutant theoretically remains consistent in your home and necessitates constant use of an air purifier.

“It's more on the consumer experience and user interaction, having it running all of the time, versus the fundamental scientific principle,” says Zhao, when it comes to what makes an air purifier most suitable for pets.

The Blueair Blue Pure 511 air purifier is an effective model in its own right. In our particle-removal test, the Pure 511 cleared our smoke-contaminated test chamber air back to non-hazardous conditions in less than 20 minutes at its lowest fan setting. Every other small-size air purifier we tested took at least 35 minutes to clean the air in that same test. The Pure 511 led the way on the high setting too, clearing the room in a category-leading 7.5 minutes. Its low energy draw is the determining factor here, with among the lowest energy requirements of any air purifier, drawing just 0.0135 kilowatts per hour, even on its highest setting.

Your best bet for larger spaces regardless of pollutant type is still either the Blueair Blue Pure 311i Max or Coway Airmega 400s above, but for a space such as a bedroom where your pets stay with you at night, the Blueair Blue Pure 511 is an ideal choice.

Size: Room capacity: Filter type: HEPA SilentReplacement filter cost: $22

Most air purifiers run within a decibel range of 33 and 55, depending on the model and setting. For comparison, that’s the difference between a light rainfall -- easy to sleep through -- and a normal conversation volume -- less easy to sleep through. Noise might be a determining factor, then, if you’re looking to literally rest and breathe easy by running an air purifier in your bedroom. The quietest of the bunch is the Levoit Core Mini, whose tested volume was only 37.2 decibels, even on its highest setting. (Most other models demonstrated 44 decibels and above.)

As a purifier, the Levoit Core Mini isn’t the most powerful, but is suitable for a small bedroom. It can clear 378 square feet in an hour, but only to a particle size of 0.3 microns. This is the industry requirement for HEPA filters, but many other models offer better outcomes. In addition to its extremely quiet running volume, however, it also has the lowest energy draw, at 0.0061 kilowatts per hour, the smallest footprint, and the smallest price tag, making it a reasonable investment if you’re looking to try out an air purifier in your bedroom or other small space.

To help inform our air purifier picks, we gathered 14 of the most popular models at the CNET Labs product testing facility in Louisville, Kentucky, where we put them through a rigorous set of tests. Our goal was to determine which air purifiers offered the best performance in terms of particle removal efficiency, energy consumption and quietness, while also evaluating their respective feature sets and value.

The air we breathe isn't just air. In truth, it's a combination of human-generated and naturally occurring particles. The former is composed mostly of urban, industrial and automotive emissions of hydrocarbons, nitrogen oxides and combustion byproducts, and the latter is mostly represented by smoke from forest fires, sulfates, soot and matter from volcanic activity around the globe.

According to the EPA, some of these microscopic solids and liquid droplets, which can be made up of hundreds of different chemicals, are so tiny that it's almost inevitable to inhale them. PM10 and PM2.5, which are particles of less than 10 and 2.5 micrometers in diameter, respectively, pose the greatest risk to human health since once inhaled. They allocate deep into the lungs and even into the bloodstream, impairing the proper functionality of the lungs and heart.

"That's the size that can go into our body, into our lungs and go into our bloodstream," said Zhao. "That is the number one environmental risk factor globally. It kills about 6 to 7 million people a year," he said, due to cardiovascular or respiratory problems brought on by particulate pollutants.

Our custom air purifier test chamber uses a clear-view front panel made of plexiglass and gloved hand access, which allows us to manipulate the air purifiers, a particle counter holder for our control device, two fans that ensure proper mixing of the air and smoke inside the chamber, vent ports that ensure there is a small amount of fresh air at all times, an ignition port to light up the smoke bombs from outside the rig, and an exhaust port that removes the remaining smoke safely from the chamber and the building after each test.

The chamber is not hermetically sealed, but it's tight enough to ensure that no hazardous amount of smoke escapes to the surroundings. Our mission was to create an environment in which we exposed each air purifier unit to particle-saturated air of roughly the same concentration to assess how quickly and efficiently they get the air back to breathable conditions.

We made custom smoke bombs, which are made of 50% potassium nitrate (KNO3), 40% sucrose (sugar) and 10% sodium bicarbonate (baking soda) and included a safety fuse for igniting it at a distance. The sugar acts as our fuel source, while the potassium nitrate acts as an oxidizing agent and the baking soda ensures that our dry mixture sustains a slow and even burn.

Using the Temtop PMD331 Particle Counter, we were able to verify that 5 grams of our smoke bomb dry mixture produces roughly between 590 million and 610 million particles per meter cubed. The device is able to count particles of different sizes, including PM2.5 and PM10, and it logs this data once every 15 seconds. Although we're able to count particles of different sizes individually, it's the total number of particles we care about, which is the sum of all particles of different sizes.

We prepared a 5-gram smoke bomb, which is ignited via the ignition port after installing the air purifier and ensuring proper sealing. Once the air in the chamber becomes particle-saturated (greater than 580 million particles/m3) we turn on the air purifier in question. The data extracted from the Temtop allows us to accurately track the impact that the air purifier has on the particle count in real time.

Using a decibel meter, we measured how loud the air purifiers are at their low, medium and high fan settings. This is particularly important if you plan on having your air purifier on in your bedroom overnight and you don't want it to disrupt your sleep. We performed this test in our sound-enhancing studio to make sure that the decibel meter picked up only soundwave stimuli from the air purifiers, excluding other possible sources.

To answer this question, we used a device called Kill-a-Watt and measured how much power each air purifier consumed at different fan settings. Knowing the energy draw for your air purifier could make a difference to your energy bill.

Kenmore Smart 2300E: This is a high-functioning, consistent, fast-acting option with a reasonable price tag for its size and operation, if you're specifically in the market for a large-room or whole-home air purifier with a moderate price tag. We preferred the Coway Airmega 400s, above, merely for its stated capacity to manage particles down to 0.1 micron in size.

Levoit Core 400s: It's the most expensive medium-sized air purifier we tested but it offers great performance in all test categories. Features include Wi-Fi connectivity, voice control and the VeSync app, which allows you to monitor air quality and control the unit remotely. It's also compatible with Google Assistant and Alexa.

Medify MA-25: The performance didn't justify the price of this unit. It struggled in our particle removal test and was the loudest of the small-sized air purifiers we tested.

Kenmore 850e: This unit offers decent particle removal efficiency thanks to its three-stage filtration system and sports a touchscreen display and dimmable night light. It wasn't quite as strong a performer as the Blueair Blue Pure 511, but is equally budget friendly.

Coway Airmega AP-1512: Above-average performance overall. Sports a color-coded air quality indicator, eco-mode and filter alerts. It has an ionizer option that may enhance bacteria and virus removal, but is a feature that also has the potential for harmful by-products.

CleanForce CP-Rainbow: I was impressed by the performance of this unit. It was the fastest air purifier at removing particles at the high fan setting, removing all smoke particles in just 1 minute and 45 seconds. It comes with app control and voice command, an HD LED display for air quality monitoring and color-coded indicators. It offers just a hair fewer features than other large air purifiers.

EnviroKlenz Mobile UV: The highlight of this unit is that it comes with two UV-C bulbs to eliminate airborne bacteria and viruses. Other than that, it's quite large and heavy, sitting at 40 pounds. It took the longest to purify the air in our particle removal test, and it's quite expensive both to buy and operate.

Veva 8000: Not a lot to highlight about this unit other than the low cost and the super quiet design. It was a bottom-of-the-pack performer in our particle removal test and in terms of energy efficiency as well.

Climate change has caused wildfire activity and air pollution to increase, with smoke infiltrating areas that are typically not subject to wildfires. Although most people who suffer from severe allergies have always been aware of air quality, we are now all becoming more aware of it due to these changes. Persistent allergy symptoms, visible smoke or pet hair and lingering odors can all be indicators that you may want to consider an air purifier. Air purifiers are useful even for minor pollutants such as cooking smoke, car exhaust, occasional dust and burning candles.

Depending on your living conditions, if there are numerous pollutants affecting the air in your home, the cleaner air and increased air flow that air purifiers provide can potentially make a big difference for the quality of life (and breath) for those in your household.

If you're thinking of getting an air purifier and want additional reassurance, it may also be worth speaking to your doctor or allergist.

Read more: Do air purifiers protect against COVID-19? What about wildfire smoke?

The primary consideration in buying an air purifier for home use is how much square footage you need to cover. Trying to save money by getting a smaller air purifier than what you actually need will just give you disappointing results. Our picks for the best air purifiers all have high proficiency, so any one of them will effectively clean the air in your home, provided they're the correct size, placed appropriately and the filters and pre-filters are maintained accordingly. After room capacity, the amount of space the device itself takes up may be important to you as well.

When considering your budget for an air purifier, you might also want to consider not only its purchase cost, but the cost of replacing the filter roughly every six months.

While this list consists only of air purifiers that include a HEPA air filter, which are the most available and highest-functioning models on the market, several of them use more than one type of filtration technology. To better understand those aspects of your air purifier, or if you want to consider buying another type of air purifier, here's a breakdown of all of the different methods of air purification technology:

HEPA air purifiers: Standing for "high-efficiency particulate air," air purifiers with HEPA filters -- defined by the U.S. Department of Energy as High Efficiency Particulate Air filters -- use a fiberglass filter that traps particles of a certain size out of the air. To be HEPA compliant, air filters must remove 99.97% of particles that are .3 microns in size and larger.

A HEPA filter can effectively remove smoke particulates from the air.

Air purifiers are small, household appliances that use one or more of a variety of technologies to filter particulate matter out of the air, including dust, allergen and viruses and recirculates cleaner air back into your living space. Air purifiers that have HEPA filters are the most popular type available, with many models employing other types of filters in addition to a HEPA filter.

Activated carbon air purifiers: Where HEPA filters manage solid particles in the air, most of the air purifiers on this list also include activated carbon or activated charcoal technology, whose porous nature helps filter gasses or volatile organic compounds out of the air. Gasses in your home air typically present themselves as odors from pets, cigarettes or cooking.

Air quality is a real concern for many Southern California residents with smoke from wildfires and smog having been linked to numerous respiratory diseases.

Negative ion air purifiers: Ionic or negative ion air purifiers work by using high voltage to give an electrical charge to particles or molecules in the air, which causes them to clump together and seek out positively charged molecules with which to bond. Certain models that use this type of technology also include a positively charged collector plate that the ionized particles will stick to, taking them out of the air. (Without a collector plate, these particles are no longer circulating in the air, but may hang on surfaces to be cleaned or vacuumed out of your home.) Most models employing this technology don't use fans, which requires more time to filter the air in a room but also makes for extremely quiet conditions. Many experts caution against this type of air purifier, however.

"Those kinds of filters essentially are not necessarily removing contaminants from the environment, but converting them to dust and surface contamination," says Masri. "And one of the issues with those is you can generate a byproduct, which is ozone. So you exchange one pollutant for another."

UVGI air purifiers: "Ultraviolet germicidal irradiation" air purifiers are similar in mechanical function to HEPA air purifiers, in that they use fans to recirculate the air to purify it quickly. Inside the device, UVGI air purifiers rely on shielded ultraviolet light to neutralize dust and allergens. This type of technology isn't available in air purifiers for home use and is typically employed in larger systems available for public settings such as office buildings.

CADR stands for Clean Air Delivery Rate, which is a measure of an air purifier’s ability to clean the air, measured in cubic feet per minute. According to the Association of Home Appliance Manufacturers, “the CADR of your air cleaner should be equal to at least two-thirds of the room’s area.” So, for example, a 10-foot by 12-foot room with an area of 120 cubic feet would require an air purifier with a CADR of 80.

HEPA air purifiers, which represent the vast majority of those on the market, are the most capable of decreasing health risks associated with air pollutants because of their ability to filter particular matter down to a microscopic size that our mouths and noses can’t naturally filter. “That’s the gold standard that's used anywhere in hospitals, in surgery operation rooms and in airplanes,” according to Zhao. All HEPA filters can manage particles down to PM 0.3, with several models offering protection down to PM 0.1.

An air scrubber is “a very, very powerful, industry-level air purifier,” said Zhao, which is the kind of large device that is used in “factories, hospitals, warehouses, or military settings.” Air scrubbers use technologies similar to those of home air purifiers, but on an industrial scale and are often built into ventilation systems. UV-C light is often used for germicidal purposes in an air scrubber.

Air purifiers don't affect the level of oxygen in the room in any way. Your air purifier is recirculating the air already in the room and cleaning it by passing it through a filter where microscopic, solid particles are removed. It is neither removing or adding additional oxygen into the space. Air purifiers are also not the same as freestanding air conditioners, although the increased airflow from an air purifier may make the air in your home appreciably cooler.

Depending on its design, an air purifier should be placed as centrally in a room as possible, to make sure that all access points of the purifier are open to receiving air. Some circular models have 360-degree functionality, while others may only be collecting air from particular faces of the device. In either case, an air purifier shouldn’t be placed directly against a wall and should allow for at least several inches of clearance. Placing it near doorways and vents that are also creating airflow may help with your air purifier's efficiency.

For maximum air purifier efficiency, it's important to isolate the air purifier within a defined space, which can be more difficult to do in open floor plans. For the best efficiency both in terms of clean air and energy uses, also keep windows closed when using an air purifier.