- An air purifier can help clean your indoor air of pollutants, dust, and smoke.
- We tested and researched more than 10 air purifiers to determine the best for your needs and budget.
- The Blueair Blue Pure 211+ can clean a 650-square-foot room in 15 minutes and indicates when to replace filters.
An air purifier can help improve the quality of your indoor air, which can be more polluted than outside air. Things like candles, cooking grease, and cleaning products can contribute to irritants, and if you’re not opening your windows 24/7, they can pollute your indoor air.
Our guide recommends air purifiers that are easy to maintain, remove a broad array of irritants, and performed well in our tests. When we examined each model, we considered its Clean Air Delivery Rate (CADR), noise level, long-term costs, maintenance, and filtration systems. We also noted how easy they are to use, as well as other useful features.
We explain our testing methodology here, along with other models we looked at that didn’t make the cut and air-purifying techniques.
Here are the best air purifiers of 2021
- Best air purifier overall: Blueair Blue Pure 211+ Air Purifier
- Best budget air purifier: Honeywell HPA300 True HEPA Air Purifier
- Best wall-mounted air purifier for large rooms: RabbitAir MinusA2 Ultra Quiet HEPA Air Purifier
- Best smart air purifier: Coway Airmega 400 Smart Air Purifier
- Best ionizing air purifier: Coway AP-1512HH Mighty Air Purifier
The Blueair Blue Pure 211+ Air Purifier filters the air in medium-to-large rooms up to five times per hour, and it’s so quiet that you won’t notice it’s operating.
Pros: Does an excellent job of removing dust, pollen, and smoke; indicator lets you know when to clean/replace filter; attractive appearance; easy to use
Cons: Filter replacement is expensive
The Blueair Blue Pure 211+ Air Purifier is designed to remove bacteria, mold, pet dander, dust, pollen, viruses, and other airborne pollutants. And, with a Clean Air Delivery Rate (CADR) of 350 cubic feet per minute, it can clean the air in a 650-square foot room approximately four times in an hour. Plus, it’s small and lightweight enough for you to effortlessly move it from one room to the next.
The Blue Pure 211+ has three-stage filtration: a fabric pre-filter, particle filter, and carbon filter. And, the unit tells you when it’s time to clean or replace the filter. Replacing the filter can be quite pricey though it should be done every six months to ensure you continue to breathe properly filtered air. The Blue Pure 211+ is Energy Star-certified and has relatively low energy costs (using 30 to 60 watts).
Another nice feature is that it runs quietly, ranging from 31 decibels on its lowest setting and 56 on its highest — quiet enough to use in a bedroom.
Last year, the Blueair 211+ was sold out at many online retailers or were selling at marked-up prices due to the California wildfires and the pandemic. The purifiers are more available now, and we never suggest buying items that are marked up if you can help it.
The best budget air purifier
If you’re looking for an air purifier that offers an impressive balance of price and performance, the Honeywell HPA300 True HEPA Air Purifier is your best bet.
Pros: Affordable; intuitive controls; easy to transport; does a very good job of removing smoke, dust, and pollen
Cons: Complaints of odors; might be too loud on high speed for some; expensive replacement filters
Honeywell is a trusted brand when it comes to air purifiers, and the HPA300 True HEPA Air Purifier is the company’s most acclaimed model. In a crowded field of expensive models, this Honeywell unit does the best job of balancing performance with price.
It has an activated carbon pre-filter, which needs to be replaced every three months, and three HEPA filters, which need to be replaced every year. A year’s supply of replacement filters will cost around $70, so the operating cost is quite high. An indicator light lets you know when it’s time to change the filter.
The biggest drawbacks are the high costs for filter replacement and operation.
This was also previously available on Walmart via third-party sellers, which we don’t recommend as shipping dates and prices are unreliable, and return policies are dubious at best. Thankfully, the item is available via Honeywell directly now.
The best wall-mounted air purifier for large rooms
The RabbitAir MinusA2 Ultra Quiet HEPA Air Purifier can be mounted to a wall for an attractive and unobtrusive appearance.
Pros: Low filter and operating costs; silent operation; wall-mounted; outstanding at removing particulate matter; attractive appearance; five-year warranty
Cons: Expensive upfront cost
When installing an air purifier, you not only have to account for the space the unit takes up, but you also have to provide clearance around it to allow for airflow. When real estate is at a premium and appearances are important, the wall-mounted RabbitAir MinusA2 Ultra Quiet HEPA Air Purifier addresses this.
The MinusA2 has a six-stage filter: pre-filter, medium filter, patented BioGS HEPA filter, charcoal-based activated carbon filter, optional negative ion generator, and a customized filter. The custom filter is unique in that you can choose to target toxins, odors, pet dander, or germs depending on your needs. The filter replacement kit is expensive, but you only need to budget for it every two years or so.
This is one of the larger air purifiers we’ve come across and can clean rooms up to 815 square feet. It’s also a good option if your space is open concept — since there are fewer walls and doors, you can clean multiple rooms at once.
This was previously only available on Amazon via a third-party seller, which we don’t recommend, but it’s now available on Amazon via the RabbitAir store directly.
The best smart air purifier
The Coway Airmega 400 Smart Air Purifier barely makes any sound and adjusts the fan speed based on the air’s pollution level.
Pros: Quiet; attractive design; energy-efficient; cleans the air in a 760-square-foot room in 15 minutes
Cons: Expensive filter contributes to the overall price
The Airmega 400 Smart Air Purifier is Coway’s top-of-the-line model. It features two sets of filters on each side of the unit: the easy-to-clean pre-filter and the Max2 filter, which is a combined True HEPA filter and activated charcoal. When it’s time to change the filters, the indicator light turns on. The Airmega 400 can monitor the air quality and adjust the fan speed to quickly filter the air.
I tested this air purifier on the main floor of my home in a centrally-located spot. Although it’s designed for rooms up to 760 square feet, it still did a great job in my open, 1,400-square-foot area, filtering the air in about 15 minutes.
On Smart mode, the fan speed ramps up when I get overzealous with my meat searing in the kitchen. After a year of use, I’m just now nearing the end of the original filter’s lifespan. Replacing the filters is incredibly pricey, however.
While some recommend the Wi-Fi-enabled version, the Airmega 400S, the only real difference between the 400S and 400 is the app-connectivity and Amazon Alexa compatibility. Other than that, performance is essentially the same.
This was previously out of stock at many online retailers but it’s more readily available now.
The best ionizing air purifier
In addition to three filters, the Coway AP-1512HH Mighty Air Purifier includes ionization, and the fan speed adjusts based on the air quality.
Pros: Automatically adjusts fan speed based on pollutants in the air; timer; four-stage filtration; eco mode
Cons: High power consumption, gets loud on high
Coway is one of the top names in air purifiers and the Coway AP-1512HH Mighty Air Purifier is its most popular model. It has an array of high-end features, including an air quality indicator, an auto mode that adjusts the fan speed to the air quality, and a shut-off timer.
The Mighty has a CADR of 246 cubic feet per minute for dust, 240 for pollen, and 233 for smoke, which makes it a good option for rooms of up to 460 square feet. The air goes through four filter stages: pre-filter, odor filter, true HEPA filter, and an ionizer. An ionizer electrically charges air molecules for purification; it can lower bacterial infections by removing particles in the air. But note that the effectiveness has been questioned and may emit ozone. Fortunately, any ozone exposure is minimal, and you can turn the ionizing feature off if you’re concerned.
The Coway Mighty is one of three air purifiers I’m currently running in my home. My son has it in his bedroom so we can minimize our home’s “teen odor index.” We’ve had it for a year, and it does an outstanding job. And, I like how easy it is to clean the pre-filter: When the indicator light tells me it’s time for cleaning, I just run a cordless handheld vacuum over it. So far, I haven’t had to replace the filter, but it’s pretty affordable and it lasts for a year.
If you’re looking for a similar model, Coway has a newer version called the Airmega 200M. Based on our testing, the 200M is more powerful but is otherwise similar in performance to the Mighty. Depending on the color, you can sometimes find the newer Airmega 200M to be significantly cheaper than the Mighty. If you come across this, we suggest going with the cheaper of the two because the performance is so similar. We think you’ll be satisfied with either.
The Mighty didn’t experience discernable shipping delays or inventory issues previously and is readily available on Amazon.
What else we recommend
While researching this guide, we looked at numerous models and brands of air purifiers. Many of them just missed the cut, but are otherwise strong products in their own right. Here are five that almost made it:
Our testing methodology
When I test an air purifier, there are several things I look for such as the rate at which it cleans, noise level, and more.
In addition to hands-on testing, I turn to other established reviewers, such as Wirecutter and Consumer Reports, for their assessments. Based on my and other experts’ research and testing, and looking through the manufacturers’ specs, I’m able to compare the key performance indicators of the top models.
Here are the main attributes when testing air purifiers:
CADR: Clean Air Delivery Rate is a rating developed by the Association of Home Appliance Manufacturers that is used to determine how many cubic feet of air an appliance can clean in a minute. If you multiply the CADR by 1.875, you can determine what room size the air purifier can clean four times in one hour, which is the recommended minimum number of air changes per hour (ACH). This calculation assumes an average ceiling height of 8 feet. Don’t worry if this sounds confusing: We put it in easy-to-understand terms in our guide.
Noise level: A good air purifier will operate in the background without most people noticing it. Loud air purifiers are a deal-breaker. I use a sound meter positioned four feet from the air purifier and measure the decibels when the fan is at its lowest speed and highest speed. The average unit should register less than 40 decibels (like light rain) most of the time and about 60 decibels (normal conversation) on high.
Long-term costs: Air purifier filters don’t last forever. They need to be replaced every 3 to 24 months, depending on the type of filter. When buying an air purifier, you need to factor in filter costs and operating expenses. Look for Energy Star-certified units if you want to save money on electricity.
Maintenance: If your filters are dirty, then they won’t perform well. You need to clean your filters regularly. I prefer an air purifier that tells me when it’s time for a cleaning. A cordless hand vacuum is all you need to clean most filters. You can clean some with water, but read the user’s manual to make sure it’s okay before doing this, and be sure to thoroughly dry the filter before using it again.
Filtration: You want a true HEPA or HEPA-type filter that can remove at least 99.97% of 0.3-micron airborne particles. The purifiers in our guide all meet this requirement. Additionally, some models have ionizers. Ionizers are controversial, but they reportedly produce negative ions that cling to air pollutants, which makes them easier to filter or vacuum up.
What we’re looking forward to testing
We’ll continue to test our top picks to see how they hold up long-term. In the meantime, here are other air purifiers we’re looking to test for future updates to this guide:
FrescheAir ($99.99): This is a portable air purifier and deodorizer, so it’d be interesting to see how the smaller size might affect the performance.
Rx Air 400 ($899.99): This is one of the most expensive air purifiers we’ve seen so it’d be great to see how the quality stacks up to others we’ve tested. It’s also labeled as a Class II Medical Device, which other air purifiers are not.
IQAir Atem Desk Personal HEPA Air Purifier ($399): While most air purifiers are meant for a whole room, this is meant for personal use at a desk or table.
PURO²XYGEN P500 Air Purifier ($189.97): This is among the least expensive air purifiers we’ve seen so it’ll be a good contender for our best budget pick. Like the RabbitAir, this has a six-stage filtration system, and it’s effective in smaller spaces up to 500 square feet. It’ll be interesting to see how its low price
Why do I need an air purifier?
Air purifiers can help clean indoor air of incense, cooking grease and smoke, and more — basically, it does what its name implies. For those with allergies, it can also help clear the air of pollen, pet dander, and more.
According to the EPA, air purifiers outfitted with a HEPA filter are an effective way to remove particles from smoke and ash and can be particularly helpful in improving symptoms for individuals with asthma or COPD that are triggered by wildfire smoke.
What does HEPA mean?
HEPA stands for “high-efficiency particulate air.” As defined by the EPA, HEPA filters are able to capture at least 99.97% of all airborne particles, including dust, mold, bacteria, and pollen, that are 0.3 microns in diameter.
Are all your picks true HEPA filters?
No. That said, we generally give true HEPA filter models preference in our picks. However, there are some “HEPA type” models that perform just as well or better than true HEPA filter models and have features that make them a better pick. We make a point of specifically saying if a model has a true HEPA filter.
Can an air purifier prevent the spread of the novel coronavirus?
If you’re considering an air purifier to help protect against the novel coronavirus, according to the EPA, a portable air cleaner by itself is not enough. However, when used along with other best practices recommended by the Centers for Disease Control and Prevention such as hand washing and social distancing, operating an air cleaner can be part of a plan to protect you and your household.
Can HEPA or H13 purifiers capture viruses, including the coronavirus?
HEPA air purifiers help with the coronavirus but won’t completely eliminate it, says Dr. Ravi Pandey, an internal medicine specialist in South Florida. He adds that the virus is smaller than what air purifiers generally capture. Most viruses, including the coronavirus, are 0.06 to 0.12 microns. HEPA filters are designed to filter out at least 99.97% of airborne particles 0.3 microns in size.
However, while an air purifier alone isn’t enough, it can be another tool for protection when used in conjunction with social distancing, hand washing, and mask wearing.
Where do you put an air purifier?
You’ll likely want an air purifier in your bedroom, living room, or kitchen — these are common areas that get a lot of traffic, and in the case of your kitchen, might help remove smoke from cooking.
How do you use an air purifier?
Most air purifiers just need to be plugged in to start working — there’s usually no installation or setup involved (unless you’re trying to connect to an app).
Place an air purifier about a foot away from the wall and plug it into a nearby outlet. If your model has an indicator light, it might say that the air is very polluted so make necessary adjustments such as opening a window or vent.
Once the air has cleared as indicated by the air purifier, keep it running to ensure continuous cleaning. Some of the models in our guide have timers so you can set it and go about your day.
How often do you change the filter?
This depends on the manufacturer’s guidelines — some suggest every three months while others say every two years.
Can plants help clean indoor air?
Think again before filling your house with plants. A 2019 article in The Atlantic cites research showing that indoor vegetation will not remove significant pollutants from the air.
How can you keep your air clean if you don’t have an air purifier?
Intense wildfires that raged in California and Oregon in 2020 burned more than 3 million acres, displaced hundreds of thousands of people, and blanketed cities hundreds of miles away from the epicenters in ash and eerie orange skies. Between wildfires and the novel coronavirus, air quality is at the forefront of many minds.
With so many people struggling with poor indoor air quality, we spoke with Dr. Junfeng Zhang, Ph.D., Professor of Global and Environmental Health at Duke University, for advice on what you can do if you don’t have an air purifier.
Dr. Zhang is particularly concerned about how individuals with asthma, COPD, heart disease, and other pre-existing diseases will cope with the poor air quality on the west coast, which is currently the worst in the world. “In the absence of a HEPA-based air purifier,” Dr. Zhang said, “I’d suggest that people, especially those who are more susceptible/vulnerable, wear N95 face masks, even when staying indoors.”
Unfortunately, true N95 masks are still hard to come by and should be reserved for medical workers but there are some more widely-available alternatives, such as KN95 masks, which can provide a decent level of filtration. The CDC has released respirator assessment results for some of these. There is a lot of misinformation and counterfeit products floating around, so be extra cautious in ensuring that you’re buying from a trusted seller.
If you are one of the lucky ones with an air purifier, remember to clean your filter thoroughly and often so it can do its job. But for an effective multi-pronged attack on pollutants, you’ll want to test and improve your air. Here’s how to test and improve indoor quality and a few steps you can take to clean your air more effectively:
- Clean regularly: Irritants can collect on surfaces and cause sneezing fits when disturbed. When you clean regularly — including dusting and vacuuming — you remove allergens and more. Check out our guides for the best vacuum cleaners, best robot vacuums, best budget vacuums, and best cordless vacuums.
- Ventilate: This could include installing ventilation fans in your bathroom or kitchen, or running (well-cleaned) ceiling fans. Freestanding fans can also help clean air circulating, here are the best ones. Be sure not to open windows or doors to prevent polluted air from coming inside.
- Store chemicals outside of your house: Abrasive cleaners and other harsh chemicals are often a source of irritation. Store them in your shed or garage and not where you will be exposed to them regularly.
Check out out other in-depth guides