Best Air Purifiers

The 25 Best Air Purifiers for 2021: For Smoke, Pets, and Allergies

Anyone who suffers from allergies or asthma knows how vital clean, fresh air is for good health.

Unfortunately, indoor air quality can deteriorate quickly. You can keep the air in your living space clean by using a quality air purifier. Our choice for the very best air purifier is the Honeywell True HEPA HPA300 Air Purifier. Made by leaders in the industry, the HPA300 is Honeywell’s best and most efficient model — and it comes at a very competitive price, too.

In-home air purifiers have been around for a while — at least since the 1960s — but over the past couple decades, filtering and airflow technologies have made them way more effective at removing all kinds of pollutants from the air. And this is definitely good news.

There are millions of people who suffer from allergies and asthma – at least 50 million in the U.S. alone – so the refinement of consumer air purifiers has enabled many people to have a better quality of life.

Leonardo da Vinci theorized air filtration in the 15th century: He suggested soldiers cover their mouths with water-soaked cloth to keep harmful gases from getting into their lungs. Ever since then, the basic idea of air filtration has remained the same: pass as much air as possible through a filter so it comes out the other side clean as a whistle! With so many air purifiers on the market, how do you know which one is right for you? We are here to help! After lengthy and painstaking research, we drew together the following ranking to help you choose the best air purifier for your needs.

Honeywell True HEPA HPA300 Air Purifier

There has been significant legislation across the globe to help clean up the air we breathe to stay alive. The United States implemented a series of laws which all sought to address outdoor air pollution: The first major act was in 1955, followed by the 1963 Clean Air Act, which established a research regime to keep track of air pollution.

The most important piece of legislation was the 1970 Clean Air Act because it established initial standards for clean air and put limits in place for automobile emissions. Additional amendments followed this act, in 1970 and later in 1990. All of these acts have helped reduce air pollution, creating a safer environment in which human beings and other animals can thrive.

Indoor Air Quality

Tending to the air quality outdoors is accompanied by an attempt to improve air quality indoors. Though there is no major legislation on the same level as the Clean Air Act, there is now a great deal of research on the causes of indoor air quality deterioration.

There are several culprits: Molds and other allergens can be common indoors. Most indoor molds or allergens actually come from outside, and since mold is so small and lightweight, it travels rather easily.

Secondhand smoke from tobacco use is also a culprit. Then there are other gases like radon, which comes from deteriorating rock and sometimes even from building materials used in construction.

There are also volatile organic compounds or VOCs, which are gases released from a large array of products like paint, cleaning supplies, pesticides, and even home furnishings. There are a number of laws to restrict the use of materials that emit these types of gases, some of the most effective of which are in Europe.

Alphabet Soup

Though air purifiers cannot yet deal with all of the pollutants listed above, they are nevertheless helpful for improving indoor air quality.

Air purifiers come with an array of materials, measurements, and testing methods to prove whether it’s really doing its job. Some of the most important acronyms are listed below:

HEPA or High Efficiency Particulate Air Filter

The HEPA filter is now an industry standard. These filters were designed during the second World War as scientists worked on the Manhattan Project. The army developed them to protect scientists and soldiers from airborne radioactive particles. They were later commercialized in the 1950s and have since been refined further.

These filters are capable of capturing up to 99.97% of airborne particulates 0.3 microns or larger. The filters themselves are typically made of fiberglass fibers, usually arranged in a random fashion to ensure a high degree of filtration.

CADR or Clean Air Delivery Rate

If you have a high-efficiency air filter, you expect to have clean air. But that assumption is incorrect. In addition to a high-efficiency air filter, you need a machine strong enough to cycle the air through the filter so that particles in the air can actually be removed.

The combination of air volume and actual filtration is what makes up the CADR of a machine. The CADR measures the amount of particles a machine can remove from the air in a room over a specific amount of time.

Because different filters are able to remove different particulates at different rates, CADR is usually given in three measurements: smoke, pollen, and dust.

The CADR measurement was developed so consumers would not be duped by machines that say they can filter a large volume of air, but don’t actually filter much at all. The CADR also protects consumers from machines that use highly efficient filters, but don’t cycle enough air to make much of a difference.

AHAM or Association of Home Appliance Manufacturers

Holmes Desktop Air Purifier

The AHAM was founded to develop and oversee standards for various types of household appliances. Though they represent the manufacturers of these products, their standards are recognized by the American National Standards Institute, the Environmental Protection Agency, and the U.S. Department of Energy.

The AHAM oversees voluntary testing and certification of a variety of appliances, including air purifiers. These are the folks who issue CADR ratings. They do not perform the tests themselves, but instead use a third party. The results are then submitted to the AHAM, who issues a seal for the product.

For air purifiers, these three acronyms — HEPA, CADR, and AHAM — often appear in reviews and on the products themselves. They are important to know when considering which air purifier best meets your needs.


We developed our rankings of the best air purifiers through careful and extensive research, including thorough meta-data analysis of several trusted review sites, hours of online research, and listening to and reading reviews from industry experts, doctors, engineers, and average folks who want better air quality in their homes. We also used the products ourselves, testing them to see if they hold up to their lofty claims.


Through this research, we developed a series of key criteria to judge which air purifier is the best, including:

  • Filtration effectiveness: Why else do you buy an air purifier? How effective is the device at removing pollutants?
  • Reputation and warranty: Is the product made by a company you can trust? How extensive is the warranty?
  • Filtration method: What kinds of filtration techniques does this machine use? Does it really use a HEPA filter? Is the activated carbon filter large enough to do the work?
  • Price: How much is this machine going to cost? And not only on the front end – is it energy efficient, and how pricey are the filter replacements? Most important of all, is it worth the cost?
  • Coverage: How large of a space is the device capable of filtering? How powerful is the air intake and how rapid can it clean the air in a room?
  • Noise: Does it sound like a purring kitten or a jet engine? It makes a difference!
  • Ease of use: Is this a set-it-and-forget-it device? How easy is it to change the filters?

These are some important questions to consider as you decide which air purifier is right for you. So before you head out or go online, take a look at our rankings of the best air purifiers. Your lungs will thank you!

Quick Navigation

Best Air Purifiers for Smoke

Winix PlasmaWave 5300 Air Cleaner

Our top recommendation is the Winix PlasmaWave 5300 Air Cleaner. Though Winix offers several different air purifiers, this model is one of the least expensive. Even at a lower price point, it still retains the quality and effectiveness of the other models.

This device includes a three-stage filtration process, which includes the standard activated carbon pre-filter to remove odors and other gases from the air. There is also an industry-standard HEPA filter. The last filtration stage is the PlasmaWave technology which functions like an ionizer without releasing harmful ozone. The PlasmaWave technology emits negative and positive ions, creating plasma clusters that attach to viruses, vapors, and bacteria, rendering them harmless.

The Winix PlasmaWave 5300 Air Cleaner is capable of cleaning the air in a 350 square foot room, and features three different speeds. It is exceptionally quiet even at the highest speed, making it ideal for the bedroom, where noise is often a concern.

The device includes a filter indicator to tell you when to change it out so the machine can run optimally. Replacement packs are relatively easy to get and are inexpensive.

This machine is very easy to operate and is usually available for under $200 – making it a great deal!

See our full ranking of the best air purifiers for smoke.

Honorable Mentions

GermGuardian AC4825 3-in-1 Air Purifier

GermGuardian AC4825 3-in-1 Air Purifier

From Guardian Technologies comes the GermGuardian AC4825 3-in-1 Air Purifier, a three-step air purifier that incorporates not only the industry-standard activated carbon filtration for odors and gases, but a HEPA filter to collect 99.97% of particles 0.3 microns or larger.

The GermGuardian also uses UV-C light technology to kill various germs, viruses, and bacteria. The device is capable of covering a smaller room of about 155 square feet. This device is not only good at eliminating odors like tobacco smoke, but can also remove substantial amounts of pollutants at a great price!

Shop the GermGuardian AC4825 3-in-1 Air Purifier


Levoit LV-H132 Purifier with True Hepa Filter

Levoit LV-H132 Purifier with True Hepa Filter

Our next air purifier is another affordable device. The Levoit LV-H132 purifier is a very compact device that gives excellent filtration, though the coverage is a bit limited. This device features a three-stage filtration process. The first stage is a nano-silver pre-filter which is designed to capture airborne bacteria.

The second stage is a HEPA filter to remove most fine particles from the air. The final stage is an activated carbon filter which captures most odors and is very effective at dealing with VOCs. The only limitation on this compact machine is its range: It can only cover about 85 square feet. However, the price point makes it easy for you to buy a second device should you need it!

Shop the Levoit LV-H132 Purifier with True Hepa Filter


Coway AP-1512HH Mighty Air Purifier

Coway AP-1512HH Mighty Air Purifier

Produced in South Korea, the Coway AP-1512HH air purifier is our last runner up. You may not know, but South Korea has serious air quality issues, owing it especially to pollution coming from China. These folks know what they are doing when it comes to producing a quality and effective product.

The AP-1512HH air purifier has a four-step filtration process, including an activated carbon filter and a HEPA filter. There is also a micro-mesh filter for larger particles, as well as an ionizer. Though a bit pricier than some of the other air purifiers on our list, this device comes with a number of nice features and does a great job at removing unwanted home pollutants.

Shop the Coway AP-1512HH Mighty Air Purifier

Best Air Purifiers for Pets

Honeywell True HEPA HPA300 Air Purifier

Our top air purifier for removing pet dander, odors, and hair is also our best overall air purifier: the Honeywell True HEPA HPA300 Air Purifier. Honeywell has been producing air purifiers for over 75 years, and they are known worldwide as engineering innovators. Their reputation for producing durable and effective products is definitely evident in the HPA300.

This machine features a two-stage filtration process, including an activated carbon pre-filter and three HEPA filters to remove 99.97% of all particles 0.3 microns or larger. For comparison, most pet dander is larger than 2.5 microns, meaning these filters are designed well enough to handle it.

Additional good news is that the replacement filters for this machine are very inexpensive at around $20 a filter.

This machine is also powerful enough to clean the air in a room of about 465 square feet. And, because it doesn’t use a 360 degree air intake system, you can actually place it in a corner.

Some additional features include a timer so you can program the machine to run between two and eight hours. You can also dim the lights on the LED panel if you decide to use it in your bedroom.

At a price point of around $300, the HPA300 is a significant investment, but the various features, filtration effectiveness, and five-year warranty make it an excellent machine to consider for your air purifying needs!

See our full ranking of the best air purifiers for pets.

Honorable Mentions

Hamilton Beach TrueAir Allergen-Reducing 04384 Air Purifier

Hamilton Beach TrueAir Allergen-Reducing 04384 Air Purifier

Our first runner up for best air purifier for pet dander is the Hamilton Beach TrueAir Allergen-Reducing 04384 Air Purifier. This option is one of the least expensive on the market, but it still gives great quality air filtration. And that low price is welcome news, since owning a pet can often be expensive.

This device features a three-stage filtration process, including a permanent HEPA filter that can be vacuumed every three to five months or so. Because of its size, the Hamilton Beach air purifier can only cover about 145 square feet, which is certainly on the smaller end. But the price means you could pick up a second one without much trouble.

Shop the Hamilton Beach TrueAir Air Purifier


Winix WAC9500 Ultimate Pet True HEPA Air Cleaner

Winix WAC9500 Ultimate Pet True HEPA Air Cleaner

Winix makes many great air purifiers, and the WAC9500 is ideal for dealing with pollutants related to pets. This machine has a four-stage filtration process including a HEPA filter to capture 99.97% of particles 0.3 microns or larger.

As with other Winix machines, this one also includes the patented PlasmaWave technology, which is an ion-based filtration system that doesn’t produce ozone like other ionizers. The machine is also energy efficient and Energy Star rated. The price is around $200, placing it mid-tier in terms of cost. This machine is overall very effective at handling pet odors.

Shop the Winix WAC9500 Ultimate Pet True HEPA Air Cleaner


GermGuardian AC4825 3-in-1 Air Purifier

GermGuardian AC4825 3-in-1 Air Purifier

The GermGuardian AC4825 3-in-1 Air Purifier makes an appearance on many of our lists – because it is just so doggone good at what it does! Its three-stage filtration process includes an activated charcoal layer and a HEPA filter. Though HEPA filters can be expensive to replace, you can actually vacuum them once every three to four months to extend their life cycle.

The final stage is the UV-C lamp which uses light technology to neutralize airborne bacteria and other viruses. One of the most attractive aspects of this machine is that it costs a little under $100, and ongoing maintenance is also very inexpensive.

Shop the GermGuardian AC4825 3-in-1 Air Purifier

Best Air Purifiers for Dust

Best Air Purifiers for Allergies

Molekule Air Purifier

If you suffer from allergies, you will be happy to hear about our top pick for best air purifiers for allergies. The Molekule Air Purifier boasts one of the most unique filtration methods currently on the market. Rather than capturing pollutants in a filter, the Molekule actually breaks down particulates at a molecular level.

The patented photo electrochemical oxidation (PECO) filter is the key to the process. PECO is a light-activated nanotechnology. After air passes through a pre-filter to remove larger particles, it comes into the PECO filter where nanoparticles bond to particulates in the air. When the light hits these newly-bonded pollutants, they are broken down at a molecular level and become essentially harmless.

This is really good news for allergy sufferers, because it means pollutants aren’t being stored in a filter where they can still be reintroduced to the environment. What is more, this filtering technique can collect particles 1,000 times smaller than the standard HEPA filter, making it one of the most effective filtration systems available.

The only serious downside is that it is costly. Coming in at about $850, the replacement filters aren’t cheap either. But if you want the most effective filtration device to help you get the sweet relief you deserve, this is the machine for you!

See our full ranking of the best air purifiers for allergies.

Honorable Mentions

Austin Air HealthMate HM400

Austin Air HealthMate HM400

The Austin Air HealthMate HM400 is on our list because it offers one of the most effective HEPA filters on the market. Most standard HEPA filters can remove 99.97% of particles 0.3 microns or larger. The medical-grade HEPA filter in the HealthMate HM400 can remove particles as small as 0.1 microns, making it extraordinarily effective.

This machine is large, heavy, and expensive. But alongside the highly effective filtration process, you get coverage of up to 1,500 square feet, making it one of the most powerful machines on the market. If you suffer from allergies and are desperate to get as many allergens out of the air as you can, this is definitely the machine for you!

Shop the Austin Air HealthMate HM400


Honeywell True HEPA HPA300 Air Purifier

The Honeywell True HEPA HPA300 Air Purifier is also our pick for best overall air purifier due to its efficient filtration, powerful air intake, and competitive price. And, as a product of Honeywell, you know it is a well-designed machine.

The HPA300 features a two-stage filtration process including both an activated carbon pre-filter and three HEPA filters. It can cover a medium- to large-sized room of about 465 square feet, and is powerful enough to cycle the air in a room at least five times in one hour. This quality machine may be just right for you if you are dealing with in-home allergens!

Shop the Honeywell True HEPA HPA300 Air Purifier

Best Air Purifiers for Mold

Holmes HAP242-NUC Desktop Air Purifier

One of the most inexpensive air purifiers on the market, the Holmes HAP242-NUC Desktop Air Purifier is our choice for the best air purifier for mold. This model is excellent to use in smaller spaces, where mold tends to develop first.

The device has a two-stage filtration process including a HEPA-type filter to remove most fine particles in the air. There is also an activated carbon filter, as well as an optional ionizer which should be used sparingly, since ionizers usually produce trace amounts of ozone.

It is recommended that you spend a few extra bucks and replace the filter that comes with the machine with a true HEPA filter. Replacement filters only cost between $10 and $20 depending on which you prefer. Of course, the machine itself is only $50, so spending more on a higher quality filter is worth it.

The machine is small, can easily be placed on a desk or tabletop, and can either lay flat or be turned horizontally. It can cover a 110 square foot room, making it ideal for a bedroom, small office space, or down in the basement where mold often forms.

See our full ranking of the best air purifiers for mold.

Honorable Mentions

GermGuardian AC4825 3-in-1 Air Purifier

GermGuardian AC4825 3-in-1 Air Purifier

Produced by Guardian Technologies, the AC4825 3-in-1 offers excellent quality for a very good price, explaining why it is the best-selling air purifier on Amazon. The machine has a three-stage filtration process, including an activated charcoal pre-filter, as well as a HEPA filter. Both of these filters are great for removing most particles from the air and eliminating unwanted odors.

The final filtration stage is a UV-C lamp, using light technology to neutralize airborne bacteria and viruses. The machine is relatively quiet, even on high, and is powerful enough to clean a 155 square foot room.

Shop the GermGuardian AC4825 3-in-1 Air Purifier


Coway AP-1512HH Mighty Air Purifier

Coway AP-1512HH

Coway is another South Korean manufacturer, which matters when it comes to air purifiers since South Korea has some of the worst air quality due to pollution from China. The AP-1512HH offers a four-step filtration process, including activated carbon and HEPA filters, as well as a micro-mesh pre-filter.

The final stage is an ionizer. The machine also has a built-in air quality monitoring system and will automatically turn on to clean the air when set on auto mode. This compact machine is also very powerful, capable of handling a 528 square foot room. And the sleek design means your air purifier won’t have to be an eyesore!

Shop the Coway AP-1512HH Mighty Air Purifier


Molekule Air Purifier

Our last honorable mention is the Molekule Air Purifier, which offers one of the most unique filtration processes on the market. Rather than capturing particles in a filter, the Molekule Air Purifier uses its own unique photo electrochemical oxidation (PECO) filter to break down pollutants at a molecular level.

The PECO filtration process is light-based, using nanotechnology to deconstruct unwanted particulates at their most basic level without producing ozone. The machine is powerful enough to handle a 600 square foot room with ease. The one downside for this machine is the price tag. If that isn’t a major concern for you, this device is definitely worth checking out.

Shop the Molekule Air Purifier

Related rankings

Do home air purifiers really work?

Air purifiers, depending on quality, are definitely capable of removing pollutants from indoor air. But that doesn’t mean they eliminate all fine particulates, nor does it mean that all of your allergies will go away.

Rather, you have to use an air purifier together with other practices like regular cleaning, dusting, vacuuming, and mopping. In addition, if you have an HVAC system in your home, make sure you have a good quality filter to help reduce dust, pollen, pet dander, and mold.

The best and most effective air purifiers use HEPA filters in conjunction with an activated carbon filter. HEPA filters, rated by the government, are only considered true HEPA if they can remove 99.97% of all particles 0.3 microns or larger. For reference, dust particles are around 0.5 microns, pet dander around 2.5 microns, human hair 5 microns, and mold spores around 10 microns.

Activated carbon filters are great for dealing with most odors. But, the larger the carbon filter, the more effective it is, since carbon filters work through adsorption. In this process, carbon filters trap gas molecules on the surface of the carbon, and once that surface runs out, the filter loses effectiveness.

Also be sure to pay attention to the CADR of your machine. The Clean Air Delivery Rate will generally tell you how much air is brought through the machine, how effectively it is cleaned, and how quickly it can accomplish this process. CADRs are actually different for each type of particle, so readings for different things like smoke or pollen are usually given for each machine.

No matter what, be sure to check out different reviews – including ours! – so you can make the right decision when choosing a good air purifier.

How do air purifiers work?

The basic idea of an air purifier is pretty simple: bring air through a filtration device to purify it. The main mechanical elements of an air purifier have to do with how to draw the air into the machine, send it back out, and how to filter it.

Most machines use a series of fans to draw air into them. Some machines draw in air through the front of the machine and send it out through the top or back. Other machines, called 360-degree airflow machines, actually draw in air from every direction.

These machines ensure more thorough and efficient airflow, though they are limited since they cannot be placed in a corner without decreasing the airflow system.

Once air is drawn into the machine, it usually passes through a variety of filters made from different materials, such as activated carbon or fiberglass. Other filtration processes are light activated or based on ionizing technology. Each of these processes offers different advantages and poses different limitations.

In the typical air purifier using a HEPA or activated carbon filter, particulates and pollutants are trapped in the filters, removing them from the air which is then pumped out of the machine and back into the room.

Since not every single pollutant can be removed in a single pass, it is important to allow the air to pass through the machine multiple times. Once the air has cycled through three to four times, most people notice a significant difference in air quality.

What is the best air purifier?

Do you have allergies? Do you need to find a way to keep dust levels in your home at a minimum? Do you have pets and want to keep your home clean and inviting for guests – even folks who may be allergic to animals? If you said yes to any of these questions, you probably want to consider using an air purifier. But there are hundreds of different air purifiers made by numerous companies on the market – how do you choose the right one? We are here to help! Our rankings were developed through meticulous research, which led us to the following questions to consider when buying an air purifier:

  • How powerful is the machine and how large of a space can it handle?
  • How loud is it?
  • What kinds of features does it come with?
  • What kinds of filtration methods does it use?
  • How effective is the filtration method?
  • How easy is the machine to use?
  • Who makes it and what does their warranty cover?
  • How expensive is it, including ongoing expenses?

These questions and others helped us to figure out the key qualities you need to consider when choosing a good air purifier.

Our research led us to choose the Honeywell True HEPA HPA300 Air Purifier as the best overall choice.

Before you make your purchase, check our list of the best air purifiers on the market!

RAVE Recommends

We also recommend these products for helping keep your home smelling and feeling clean and fresh:

  • Filtrete MPR Ultra Allergen Reduction HVAC Air Filter: Check out air filters for your home HVAC system to use alongside the HEPA filters in your air purifier.
  • RADEX MR107 Advanced Radon Gas Detector for Homes: If you are concerned about radon in your home, there are several in-home kits you can buy, and this is one of the best!
  • First Alert Carbon Monoxide Detector Alarm: Another absolute must for any home. In fact, you may want to have one of these on each level of your house!
  • “Green Building Fundamentals”: If you are at all considering making major changes to your home to improve environmental quality for your family, you should check out this book on how to use green building techniques!
  • Vacmaster 8 Gallon HEPA Vac: The best ally of a good air purifier is a really good vacuum cleaner. This is one of the best HEPA-filtered vacuum cleaners on the market!

Chris Winn

Chris Winn is a freelance writer who works in the Minneapolis area, where he and his family are beholden to two cats and a dog.