We Tried 25 Indoor Air Quality Monitors — These 9 Are the Ones We Actually Recommend

Usigan found this device provided crucial data about the air quality in her home: “We noticed a strange difference in air quality from our upstairs to downstairs,” Usigan says, describing how her upstairs air quality was almost as bad as in her garage. “We don't see anything noticeable about the air, so now we are going to check for mold. Our daughter has been getting headaches at night, and we're wondering now if there's something in the air that's making her feel off,” Usigan says.

The monitor tests for 14 different pollutants, including not just PM10 and PM2.5 but also PM1, which is particulate matter smaller than 1 micron; many monitors test only down to PM2.5. It also tests for other key pollutants and gives an overall air quality index (AQI) score that combines all the factors into one simple, easy-to-grasp number.

If you’re a fan of Apple products, you’ll probably like Qingping’s Lite Air Quality Monitor. Not only is it compatible with Apple’s Home App, but this elegant white cube would look right at home sitting in the Apple Store. Our favorite feature on this monitor was the intuitive color-coded display, which our tester, editor Katie Tuttle, found “very easy to understand. The readings are green, yellow, or red so you can see at a glance if your air quality is good or not,” she explained. The monitor displays only one reading at a time, along with a color-coded light bar. “You have to tap a button on the top of the device to toggle through different readings; it would be nice if all this information was displayed at once, or if it cycled through different readings,” Tuttle says. Still, if you don’t want a screen that gives your space that pilot’s cockpit vibe with a jumble of different readings, the single number display keeps things visually sparse and uncluttered — and you can easily view all five readings at once from your phone via the app.

One of the only downsides we found to this monitor was the setup, which Tuttle describes as confusing. “Finding the device on Bluetooth was a bit challenging since it comes up as a different name,” she explains. Also, despite giving you a reading immediately, the device needs 30 minutes in a windless area to calibrate before use. It also does not provide alerts when the air quality gets bad, although it will silently suggest you open a window if your CO₂ gets too high. 

I actually purchased this monitor on my own about a month before Everyday Health asked me to take on this write-up to test a house I was considering moving to. The house is close to a main road, and I wanted to test the air in each and every room — particularly my daughter’s bedroom — and in the backyard before deciding whether we would live there. This handheld device was the perfect solution. It takes continuous readings because it is intended for use in multiple locations in rapid succession, rather than for continuous use in a single location. The building inspector I mailed it to said he’d been inspecting houses for 20 years, and I was the first person ever to ask him to include air quality in the report. He loved this device so much that he asked if he could buy it from me.

The monitor comes with a sturdy metal carrying case, so it travels and stores well. All models measure both PM2.5 and PM10, as well as CO₂, temperature, and humidity. But if you want to test for formaldehyde and VOCs, you’ll have to opt for the more expensive version. “It was very easy to get started. I just had to educate myself on what the various readings meant,” said our tester, fitness and nutrition writer Brittany Scanniello. The device will alert if air quality is poor — but the beeping can be silenced at the touch of a button. “Everything but CO₂ was immediate,” said Scanniello, on how long it took for the device to create a reading. “The CO₂ takes about three minutes to warm up and start displaying a ppm value.” For anyone who wants a portable air-quality tool instead of a permanent countertop device, the Temtop Handheld Monitor is an excellent option.

Qingping’s air monitor moonlights as a bedside clock when it's resting, with easy-to-read analog numbers and a built-in calendar. It’s so brilliantly simple, it makes me wonder why more air quality monitors don’t double as clocks. It even has an alarm clock feature, although there are no alerts for poor air quality. “When the monitor is 'resting,' it functions as a digital clock,” says Heyl. “I liked the design. It was sleek, simple, and aesthetically pleasing.”

You retrieve the metrics by hitting the touchscreen, switching the display to a single-page view of pollution levels, each conveniently color-coded to make assessing your air quality a breeze. You can also read the monitor remotely via the Qingping app. The device is eco-friendly; you can swap out the PM sensor for a new one instead of throwing out the entire device if its accuracy starts to degrade.

Heyl found the monitor “easy to use but difficult to understand,” as it came with very little instruction (in that it was both sparse and written in a font so tiny it was difficult to read). The device does not measure formaldehyde (many monitors do not), but it does measure noise. If you’re worried that heavy noise pollution is affecting your hearing, this device can help you determine if you need to invest in some earplugs or insulation. 

Do QR code menus make you groan? If you’re someone who hates squinting at tiny digital displays, this is the air quality monitor for you. “I like that the display is clear and easy to read from a distance. The numbers are large, and there's a green light system to show your overall air quality index,” says our tester, the health writer SaVanna Shoemaker. Overall, she found this monitor very easy to use. “Just power it on and it's all set,” she says.

Aside from the large display, this monitor has plenty going for it, including a sensor sensitive enough to detect PM1. “It's clearly sensitive enough to pick up on changes in the air because the readings changed so dramatically when I burned something in the kitchen,” Shoemaker says. The display shows all the metrics at once and includes an alarm clock and an alert system that makes a noise if your air becomes polluted. The monitor does not need to be calibrated, but turning it off and on again will recalibrate the system. “It calculated results for roughly three minutes after I turned it on, but it provided a countdown timer to show when each metric would be ready,” Shoemaker says. The only thing we didn’t like was the placement of the control buttons, which are on the back of the monitor rather than the front, making them hard to find and reach. 

This cube-shaped monitor is small and simple: It centers on an AQI reading of “normal,” “warning,” or “danger,” and points to a corresponding position on a green, orange, or red dial. “The AQI is big and easy to read, and the numbers change quite a bit depending on where the monitor is,” says the writer Alexandra Klausner. If you never want to learn what PM stands for, or exactly what dangers may be lurking in your air, the AQI takes into account several different metrics to give you a generalized assessment of how clean your air is, and lets out a noise alert if the AQI rises above 100, into the “danger” zone.

If you do want to get a little more in-depth, it does also offer PM10, PM2.5, and CO₂ readings, visible in smaller readouts around the AQI score. These can help you determine whether your pollution is coming from outside (like most particulate matter, or PM) or from inside (a CO₂ buildup from a lack of ventilation), so you can decide whether opening or closing the windows will improve your air quality. “I like that I can detect CO₂ so I can make sure [my family and I] are safe,” said Klausner. The device recommends a manual calibration during setup, which simply involves placing it in a well-ventilated area, holding down all the buttons at once for a few seconds, and then waiting 3.5 minutes; you can do this anytime you want to recalibrate the device. The device will still work if you do not manually calibrate it, but this important step ensures your readings are as accurate as possible.  

Airthings is the only monitor on this list that tests for radon, a naturally occurring radioactive gas that causes cancer and is usually tested for in its own device or kit. The company prides itself on being one of the leading manufacturers of radon tests for the past 15 years, and this device bundles its radon monitor with sensors for several other common indoor pollutants, including VOCs, CO₂, and formaldehyde. It’s noteworthy that the device does not test for PM2.5 — perhaps the most common indicator of outdoor air quality — suggesting it is designed more to track dangerous gases that could be building up from sources inside the house, rather than pollution blowing in from outside. It also measures CO₂, VOCs, and formaldehyde, which tend to originate indoors and build up in poorly ventilated spaces, making this a perfect monitor for those areas of your home.

If you’re looking for more information on specific indoor pollutants, which is something most of these monitors come up short on, “Airthings has a fantastic site where they do break it all down for you — they explain it to you like you are 5 — with pictures and words. It's amazing,” says our tester, health writer Raki Swanson. This monitor lacks an external display and indicates changes in air quality via a red, orange, or green light. If your light is anything but green, you have to log in to the app to see the exact reading of what is polluting your air. Swanson found that her monitor “Immediately went red. I did read that it was going to take 7 days to calibrate (and a full 26 days for radon), so I didn't freak out over the red — but the red never went away, causing me massive anxiety,” she says. The app showed her CO₂ was high, and she wasn’t sure if the monitor was inaccurate or highly sensitive, as a separate CO₂ monitor in her home showed normal levels, but she did find that “opening windows, letting in fresh air, did change this. It went to green within an hour.”

Given Airthing’s standing in the air monitor industry, I wouldn’t discount their readings; it’s quite easy for indoor CO₂ levels to build up, particularly with all the windows closed and central air running constantly, as Swanson said was the situation in her home. While she said she had several air purifiers running, air purifiers won't reduce CO₂ — the only way to do that is to open a window.

Pairing an air quality monitor with an air purifier seems like a fantastic idea, especially when a poor air quality reading triggers the purifier to kick into high gear, like this one does. “When cooking dinner, the device turned up in level to deal with the odors and smoke, etc. It took a little longer than I'd like. The air quality monitor had been beeping for a good five minutes before I heard the purifier move up a level,” says the writer Olivia Campbell. The lag time leaves something to be desired. Another downside is that this monitor only tests for PM2.5 — it’s not going to tell you if CO₂ or VOCs are building up from a lack of ventilation. Generally speaking, this device would be better for ventilated areas, where invisible wildfire smoke or smog might creep in; its alert system could signal you to close the windows (unless you’ve been cooking, which creates PM2.5). Then it could do its job removing particulate matter and other pollutants that have blown in.

Campbell also found “it was a little tricky to open the device for changing the filter,” but that only needs to be done once a year. She did appreciate the design. “It's relatively small and sleek and would fit well with most room decor. It's not an eyesore,” she says. If you’re a fan of essential oils, this device includes a diffuser, making it a great way to clean the air and make it smell fabulous at the same time. 

If you’re into citizen science, you’re going to have a lot of fun joining the PurpleAir Community. The company has aspirations far beyond your living room: the monitor is primarily intended for outdoor use and invites you to log your monitor into their community map, which both publishes your monitor’s data and lets you read all the other PurpleAir monitors in your area. The idea is that by looking at the entire map of monitors, you’ll be able to see how air pollution is moving. If there is wildfire smoke heading toward you, or smog sitting across your entire city, you’ll see the severity and direction of air pollution trends displayed across everyone else’s monitors in real time, as well as the immediate readings displayed on your own.

If you’re only looking for an indoor air quality monitor, PurpleAir can do that too — but it’s probably not worth the steep price tag you’re paying for the weatherproof housing and the community data pool you won’t be joining. Most importantly, it only monitors PM2.5, which typically comes in from outside. It’s not going to tell you if your carbon dioxide levels are high from a lack of ventilation, if your humidity level might indicate a mold problem, or if that new couch you just unboxed is off-gassing a dangerous amount of VOCs. Still, it has an attractive, simple design, and our tester, the Everyday Health editor Ashley Ziegler, appreciated the no-screen, light-coded interface. “I like that I can just look at it and easily see what color it is. I have no interest in all the technical details about air quality, so this is a great option,” she says. She didn’t connect with the community because she was testing the monitor inside, but she found the website clunky and outdated. There is also no app, and for a monitor that prides itself on community science, the lack of one stands out as a major drawback.