Best air purifier 2023: Clear the air and take a break from your allergies

The best air purifiers can help to ease the symptoms of asthma, hay fever and other allergies by cleaning the air in your home, removing pollutants and irritants such as pollen, dust, pet dander and smoke. With good-quality air purifiers available from under £100 to well over £1,000, there are plenty of great choices for every budget.

But with machines ranging from downright useless to ultra-effective, it's essential you do your homework before you choose which one to buy. To help out, we’ve tested a selection of machines to pick out the best air purifiers you can buy – that is, the ones that quickly and efficiently clear the air and are easy to both set up and use.

We've split the products here into three groups, with models suitable for small, mid-sized and larger rooms, and you can jump to each section with the links below. If you're in a rush, then our at-a-glance list has quick buying links for all our favourite models. If you're really not sure what kind of air purifier suits your needs best, then our buying guide will explain all the key features to look out for.

Air purifiers can cost as little as £70 or well over £1,000, but it's not simply a case of the more you spend, the better the machine. Indeed, we’ve found low-cost machines with features that are usually only found in much more expensive models. But that's not to say that a pricey air purifier is inevitably overpriced; more expensive models from Philips, Sharp or Daikin will have additional modes and features that the cheaper products lack. Also remember it's not just the initial financial outlay you need to think about, with operating costs ranging from a few pounds a year up to over £70 per annum, especially if you need to replace filters once or twice a year.

Air purifiers use different kinds of filters to do their job – usually, a large, washable, reusable pre-filter to collect bigger particles, plus a finer filter, which is usually a disposable high-efficiency particulate air (HEPA) filter. The length of time this lasts varies, but on average expect it to need replacing every six months (or fewer if you use the machine less). It's the HEPA filter that catches all the tiny airborne nasties, and these are capable of catching particles as small as 0.3 microns, which is more than three times smaller than a cigarette smoke particle.

READ NEXT: The best humidifiers

The CADR aims to provide an objective measure of the effectiveness of a portable air purifier at dealing with different types of allergen. A purifier with a score of 250 for dust particles is as effective as adding 250 cubic feet of clean air per minute. Buyers should focus on the results of the specific pollutant they're aiming to eradicate, whether that's pollen, smoke or dust, and many manufacturers will supply CADR figures for the most common.

Generally speaking, the higher the CADR, the larger the room it can purify effectively. It's also worth comparing manufacturer figures for the maximum size of room as these can vary enormously, sometimes when the CADR doesn't.

Understandably, there has been a lot of talk over the past couple of years around whether HEPA air purifiers offer any protection against viruses, including Covid-19. The answer is pretty complex. Most viruses – and the droplets of mucus and saliva that might contain them – are perfectly capable of filtering particles in the 20 to 500-nanometre range in which you’d find most viruses. What's more, the US Centre for Disease Control has advised that used properly, air purifiers can help reduce airborne contaminants, including viruses, in a home or confined space.

However, there's no way to ensure that a HEPA air purifier would catch the virus prior to you inhaling it, and there are a lot of variables in play, including the type of filter used, the size of the room and the airflow in it. There's also still a lot of discussion about the extent to which many viruses are spread through the air or transmitted through contact with respiratory droplets. In short, an air purifier might help, but there's not enough evidence to make the case compelling.

We first test air purifiers in normal household circumstances to assess their features, noise levels and performance with everyday particulates and irritants, including wood smoke, pollen and pet dander. We then run standardised tests, spraying a test aerosol inside a small room for five seconds and using an air quality meter to record particulate levels. We time the period it takes to return the room to a normal level (25 micrograms per square metre) to get a base rate of purification. During testing we also measure noise levels at low, medium and maximum power settings, plus sleep settings where available, and measure power consumption.

READ NEXT: Best dehumidifiers

Price when reviewed: £89 | Check price at Robert Dyas

It's really designed for small spaces of around 10m², but we found its performance better than the 80m³/h CADR might imply. Spraying antiperspirant into a small room with the purifier at maximum speed, the Clean Air Compact brought PM2.5 particulates down to safe levels within three minutes and six seconds. At that speed it's fairly noisy, with sound levels reaching around 48dBA, but in general use the low setting will be fine, and this takes the noise levels down to 36.2dBA, where the sound is noticeable but hardly aggravating.

Spending more will get you something quieter with more power, but this is a decent little purifier for a small lounge, home office or bedroom if you’re working to a similarly sized budget.

Key specs – CADR: 80m³/h; Max room size: 10m²; Power settings: 3; Dimensions (HWD): 40.3 x 19.5 x 19.5cm; Weight: 2.3kg; Filter replacement indicator: Yes; Warranty: 2 years

Price when reviewed: £80 to £180 | Check price at Amazon

The HoMedics stays quiet at its lowest two settings, but noise levels ramp up on its highest setting to around 54.1dB, making it louder than some larger models. It uses between 16W and 34W while in use. Performance is in line with other small purifiers, taking just over four minutes to bring our PM2.5 particulates down to safe levels from a high of 387 micrograms per square metre. However, with an HEPA filter, a carbon odour filter, an ioniser and UV-C treatment to combat germs, the HoMedics has a more robust set of air treatment features than other purifiers in its class. It's affordable, but not at all basic.

Key specs – CADR: 184m³/h; Max room size: 75m²; Power settings: 3; Dimensions (HWD): 43 x 21.3 x 21.3cm; Weight: 3kg; Filter replacement indicator: Yes; Warranty: 3 years

Price when reviewed: £145 | Check price at Ikea

It uses a three-stage filter to capture larger particles and odours as well as the usual PM2.5 pollutants, and while our tests show that it's not especially powerful, it has enough air-clearing power to handle the average-sized living room and performed especially well in a well-used kitchen/diner. It's also reasonably quiet, with barely any noise at lower settings, although it reached just over 50dB at full tilt. It connects to Ikea's Tradfri smart ecosystem, so if you’ve invested in Ikea's smart bulbs and speakers, you can hook up your purifier, check the air quality and change the current settings via an app.

Key specs – CADR: 240m³/h; Max room size: 20m²; Power settings: 4; Dimensions (WDH): 51 x 19 x 53cm; Weight: 5.9kg; Filter replacement indicator: Yes; Warranty: 1 year

Check price at IKEA

Price when reviewed: £299 | Check price at Amazon

We’re not sure how well that works in practice, but the UA-HD40U-L is impressively efficient at filtering out impurities and very quiet at its automatic and low-power settings. A strip on the top turns from red to orange to green to indicate the current air quality, and there's a humidity readout so you can monitor humidity levels, although both this and the "ion shower" feature can be turned off if you just want air purification. Well designed and easy to use, this is a great air purifier for smaller rooms.

Key specs – CADR: 216m³/h; Max room size: 26m²; Power settings: 6; Dimensions: 39.9 x 23 x 61.5cm; Filter replacement indicator: Yes; Warranty: 1 year

Price when reviewed: £179 | Check price at Amazon

The minimalist aesthetic extends to the controls, with just a single button that you use to toggle through the Auto, Everyday, Night and Boost modes, surrounded by a ring of four indicators to let you know which mode you’re in. Meanwhile, the coloured indicator on the front gives you a quick appraisal of the current air quality, glowing blue to red. It's practically silent at its lowest settings, although it creeps up to nearly 50dB in Boost mode. Still, with the Auto mode so effective, it's unlikely you’ll use Boost all that often; it constantly measures the air quality and applies whatever speed it thinks is needed to keep things clean

We were impressed with the air-cleaning performance for such a small unit. During our anti-perspirant PM2.5 test it brought the levels down to double figures within a minute, and they kept on ticking downwards, where other compact purifiers seem to struggle the closer the count gets to safe levels. Throw in low power consumption – just 2.2W to 9.1W depending on the mode – and you’ve got a superb, if expensive, compact purifier.

Key specs – CADR: 181-210m³/h; Max room size: 41m²; Power settings: 4; Dimensions (HWD): 42.5 x 20 x 20cm; Weight: 1.7kg; Filter replacement indicator: Yes; Warranty: 1 year

Price when reviewed: £175 | Check price at Toolstation

Second, the 280 turns out to be something of a pocket rocket. It's not brilliant in larger rooms, but put it in a small space and it puts through air at a prodigious rate, clearing our test aerosol at similar speeds to the mighty Hoover H-Purifier 500. The downside is that it can be noisy, putting out 35dB even at its lower speeds and nearly 53dB at peak, although on Sleep mode we found it hard to hear over ambient noise levels. That aside, it's a great option for small and even mid-sized rooms.

Key specs – CADR: 280m³/h; Max room size: 35m²; Power settings: 4; Dimensions (WDH): 25 x 25 x 45cm; Weight: 3.8kg; Filter replacement indicator: Yes; Warranty: 2 years

Check price at Toolstation

Price when reviewed: £329 | Check price at Amazon

Otherwise, this has the same advantages as the smaller version: effective three-stage filtering, a built-in humidifying function and Sharp's Plasmacluster ion technology, which – while it sounds like a weapon from a Halo game – works to kill odours, bacteria and mould. While the Vax PureAir 300 gives you even more airflow and covers larger rooms for less, the Sharp hits a sweet spot for price, performance and features, making it a great mid-range purifier for mid-sized rooms.

Key specs – CADR: 306m³/h; Max room size: 38m²; Power settings: 6; Dimensions: 39.9 x 23 x 61.5cm; Filter replacement indicator: Yes; Warranty: 1 year

Price when reviewed: £550 | Check price at Amazon

The Philips AC3829/60 easily justifies its steep price, thanks to both its excellence at purifying the air in your home and its abundance of bells and whistles. In terms of the main job at hand, it's easy to set up and use and, crucially, it removes dust, pollen and smoke at a rate of knots. The purifier is also energy-efficient and quiet on the low speed setting, and although it's louder on the highest of its four fan speeds, it has a night mode to quieten it down when you’re trying to get some shut-eye.

The AC3829/60 can be controlled using a smartphone app where you can set it to "general", "allergen on" or "sleep mode". You can also find real-time pollution data both inside and outside, and get weekly forecasts, among other things. There's a timer and an automatic mode, and this model even acts as a humidifier.

All in all, it's hard to fault, but be warned that it's big – even if it does have wheels. Our one complaint would be that replacing filters could be easier. If you’re not fussed about dehumidification, you can save a little cash by going for the similar – and cheaper – AC2889/60.

Key specs – CADR: 310m³/h; Max room size: 95m²; Power settings: 8; Dimensions (HWD): 80 x 49 x 39cm; Weight: 13.6kg; Filter replacement indicator: Yes; Warranty: 2 years

Price when reviewed: £331 | Check price at Amazon

This one also has some interesting features. Its Flash Streamer technology is designed to break down pollen, fungal spores and odours with electrons, while its main HEPA filter is specified to last a full ten years. The secondary pre-filter and odour filters can just be vacuumed clean. Meanwhile, you can set the sensitivity of the PM2.5 sensor or switch to a customisable energy-saving eco mode. It's not the most attractive unit and the controls are quite complex, but if you’re looking for a quiet, powerful air purifier, this is one of the best.

Key specs – CADR: 330m³/h; Max room size: 41m²; Power settings: 4; Dimensions (WDH): 27 x 27 x 50cm; Weight: 6.8kg; Filter replacement indicator: Yes; Warranty: 1 year

Price when reviewed: £159 | Check price at Amazon

In normal operations, though, fan noise won't be a problem. While the racket is pretty awful at the highest speed, it's barely noticeable at the lowest setting and the A9 has a sleep mode that drops it down even further and turns off the display and any LED indicators.

And, if you don't fancy using the buttons on the top of the unit, you can also set timers and change the settings over Bluetooth or Wi-Fi using Proscenic's smartphone app (though why this needs access to your location and your phone's cameras and photo library is a bigger question that will put some users off). Still, with or without the app, this is a great-value purifier that makes some bigger-brand models look cumbersome and dated.

Key specs – CADR: 460m³/h; Max room size: 90m²; Power settings: 4; Dimensions (HWD): 52 x 26 x 26cm; Weight: 5.94kg; Filter replacement indicator: Yes; Warranty: 1 year

Price when reviewed: £399 | Check price at Harrods

The controls are simple, but BlueAir has also fitted Wi-Fi to the unit so that you can use it with the company's smartphone app. This works as a remote control, but also allows you to schedule when to turn it on and off, plus which mode to use, and set different schedules for different days of the week. You can also track its operations and your air quality over time. There's no fancy programmable IFTTT stuff, but this is streets ahead of other purifiers with apps.

The icing on the cake is excellent performance. In our standard anti-perspirant spray test, the DustMagnet got us down to safe levels within two minutes, with most of the work being done within the first 60 seconds. And while we had our doubts about its claims of capturing airborne dust before it settles, we did notice a lower build-up over a couple of days of testing. Normally we wouldn't want to leave it on so long, but with the DustMagnet using around 4W to 10W when set to Auto, power consumption is relatively low. Quiet, efficient and effective, it's the perfect purifier for your living room.

Key specs – CADR: 226-238m³/h; Max room size: 48m²; Power settings: 5; Dimensions (HWD): 52 x 22 x 22cm; Weight: 4.5kg; Filter replacement indicator: Yes; Warranty: 1 year

Price when reviewed: £100 | Check price at Amazon

This one has sensors for PM10 and PM2.5 pollutants along with VOC gases, and can also track temperature and humidity through the display. What's more, link it to the hOn app over Wi-Fi, and the H-Purifier 500 will respond to other changes, including high pollen levels, soaring temperatures or pollution.

What we really like about this purifier, however, is that it's both effective and pretty quiet about it. At full tilt, it's as noisy as most rival air purifiers, but in its sleep mode you’d struggle to hear it above ambient sound levels – we measured the output at just 31dBA. In our deodorant spray test, the H-Purifier 500 got the PM2.5 concentration down to safe levels within two minutes and eight seconds, and Hoover's three-filter purification system has been approved by the Allergy UK charity. We’re not 100% sure about the option to add essential oils to the airflow, but the options include an H-Biotics bottle that adds probiotic "good" bacteria to the atmosphere. All in all, it's a superior purifier that's perfect for mid-sized and larger rooms, with a price tag that won't leave you gasping.

Key specs – CADR: 330m³/h; Max room size: 110m²; Power settings: 3; Dimensions (HWD): 57.5 x 28 x 32cm; Weight: 6.9kg; Filter replacement indicator: Yes; Warranty: 2 years

Price when reviewed: £150 | Check price at Amazon

This isn't all the PetPlus has going for it. Its power consumption is surprisingly frugal – just 3.3W at the lowest of its three fan speeds – and quiet at 33dB. With the speed ramped up to max you’re looking at around 48.8W and 57dB, but you can keep it on low or medium most of the time. As for air-cleaning performance, it's exceptionally good, bringing us down to safe levels of PM2.5 within two minutes in our tests. That's one of the speediest results we’ve ever seen. While not quite as beefy or as feature-packed as the Hoover H-Purifier 500, it's a great alternative for anyone with pets.

Key specs – CADR: 303m³/h; Max room size: 125m²; Power settings: 3; Dimensions (HWD): 60 x 28.6 x 28.6cm; Weight: 4.1kg; Filter replacement indicator: Yes; Warranty: 3 years