Best air quality monitors UK (2026) — compared & price-tracked
An indoor air quality monitor tells you what is in the air of one room — usually carbon dioxide, particulates or airborne chemicals — so you can decide whether to open a window, run the extractor fan or look harder at a damp corner. What none of the monitors on this page does is replace a carbon monoxide alarm certified to EN 50291, and most of them give no warning of carbon monoxide at all. The useful question is not which unit carries the most sensors, but which readings you would actually act on: CO2 for ventilation, PM2.5 for cooking and wood smoke, radon if you live in an affected area. Prices below are tracked against UK retailers and checked against each manufacturer's own documentation.
By Tom Calder · Updated 5 November 2026 · 6 products, all price-tracked
Our picks
Photo: AmazonAirthings View Plus
One device covering radon, particulates and CO2 in the same room, with a screen you can actually read.
as of 5 Nov 2026, 22:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Photo: AmazonAranet4 Home CO2 Monitor
Knowing, from the other side of the room and without touching your phone, when to open a window.
as of 5 Nov 2026, 22:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Photo: AmazonAirthings Wave Plus
Radon and CO2 monitoring in a home that already has, or is willing to add, an Airthings hub.
as of 5 Nov 2026, 22:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.All 6 compared
| Monitor | Measures | Display | Connectivity | Power | Price |
|---|---|---|---|---|---|
Radon, PM1/PM2.5, CO2, VOCs, temp, humidity, pressure. No CO. · 2.9in e-ink screen, plus motion-activated green/yellow/red glow · Wi-Fi 2.4GHz and Bluetooth; app and dashboard; USB-C hub mode · 6x AA, up to 2 years claimed, or continuous USB-C mains One device covering radon, particulates and CO2 in the same room, with a screen you can actually read. | Radon, PM1/PM2.5, CO2, VOCs, temp, humidity, pressure. No CO. | 2.9in e-ink screen, plus motion-activated green/yellow/red glow | Wi-Fi 2.4GHz and Bluetooth; app and dashboard; USB-C hub mode | 6x AA, up to 2 years claimed, or continuous USB-C mains | £234.99 at Amazon as of 5 Nov 2026, 22:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The only monitor here that measures radon, PM2.5 and CO2 together, and the only Airthings with a proper numeric display alongside the app and web dashboard. It has no carbon monoxide sensor, so it changes nothing about your need for a certified alarm. Airthings also states the CO2 and VOC readings take around seven days to settle, so judge it in week two rather than week one. Best for One device covering radon, particulates and CO2 in the same room, with a screen you can actually read. Good
Worth knowing
Who shouldn't buy it: Don't buy it if you only care about ventilation — the Aranet4 Home measures CO2 more accurately and costs less. Read the full review → | |||||
CO2 (NDIR), temp, humidity, pressure. No PM2.5, VOC, radon or CO. · Large-digit e-ink, readable across a room, traffic-light status · Bluetooth only — no Wi-Fi; Aranet Home app for history/export · 2x AA — up to ~4 years alkaline, up to 7 years on lithium Knowing, from the other side of the room and without touching your phone, when to open a window. | CO2 (NDIR), temp, humidity, pressure. No PM2.5, VOC, radon or CO. | Large-digit e-ink, readable across a room, traffic-light status | Bluetooth only — no Wi-Fi; Aranet Home app for history/export | 2x AA — up to ~4 years alkaline, up to 7 years on lithium | £166.32 at Amazon as of 5 Nov 2026, 22:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The best CO2 instrument in this cluster by a clear margin, with a manufacturer-stated NDIR accuracy of ±(30 ppm + 3% of reading) and a display you can genuinely read across a room. It does one job properly and makes no pretence otherwise: no particulates, no VOCs, no radon and — this is the point readers most often get wrong — no carbon monoxide whatsoever. Bluetooth only, so there is no checking in on it while you are out. Best for Knowing, from the other side of the room and without touching your phone, when to open a window. Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want particulates or radon as well — the Airthings View Plus covers all three at a broadly similar price. Read the full review → | |||||
Radon, CO2, VOCs, temp, humidity, pressure. No PM2.5, no CO. · No screen — wave your hand for a red/yellow/green glow ring · Bluetooth to app; continuous sync needs a SmartLink hub (extra) · 2x AA — 16 months claimed, 18 months via SmartLink Radon and CO2 monitoring in a home that already has, or is willing to add, an Airthings hub. | Radon, CO2, VOCs, temp, humidity, pressure. No PM2.5, no CO. | No screen — wave your hand for a red/yellow/green glow ring | Bluetooth to app; continuous sync needs a SmartLink hub (extra) | 2x AA — 16 months claimed, 18 months via SmartLink | £180 at Amazon as of 5 Nov 2026, 22:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched Radon, CO2 and VOC sensing with a claimed 16-month battery life is a lot of measurement for the money. The catches are structural rather than minor: no PM2.5 sensor, no numeric screen, and no continuous cloud sync unless you buy a SmartLink hub or already own a View-series monitor — so remote alerts cost more than the headline price. Like every other Airthings here, it has no carbon monoxide sensor. Best for Radon and CO2 monitoring in a home that already has, or is willing to add, an Airthings hub. Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want particulate readings or a screen — the View Plus adds both for a modest step up in price. Read the full review → | |||||
 CO2, temp, humidity, noise level. No PM2.5, VOC, radon or CO. · No screen — press the top for a colour-coded LED summary · Wi-Fi to the Netatmo app, with Apple Home compatibility · Mains only via USB adaptor — no battery, must stay plugged in A cheap, permanently plugged-in CO2 reading in a room where noise levels are also worth knowing. | CO2, temp, humidity, noise level. No PM2.5, VOC, radon or CO. | No screen — press the top for a colour-coded LED summary | Wi-Fi to the Netatmo app, with Apple Home compatibility | Mains only via USB adaptor — no battery, must stay plugged in | £107.25 at Amazon as of 5 Nov 2026, 22:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The cheapest genuine CO2 monitor here, and the only one that also measures noise — a real differentiator in a home office or a room next to a busy road. It is old hardware for the money, it has no screen, and it is mains-only, so it goes dark the moment the power does. Its "Asthmatic", "Baby" and "Family" app profiles are adjustable alert thresholds, not health features, and should not be read as anything more. Best for A cheap, permanently plugged-in CO2 reading in a room where noise levels are also worth knowing. Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want a CO2 figure you can read at a glance without your phone — the Aranet4 Home has the display for it. Read the full review → | |||||
 PM2.5, VOCs (low/med/high), CO, humidity, temp. No CO2, no radon. · No screen — one status LED; all readings live in the Alexa app · Wi-Fi and Bluetooth; Alexa app, Echo voice readouts and routines · Mains USB only — no battery, so it stops in a power cut Particulate readings in an Alexa household, at a price that regularly drops a long way below list. | PM2.5, VOCs (low/med/high), CO, humidity, temp. No CO2, no radon. | No screen — one status LED; all readings live in the Alexa app | Wi-Fi and Bluetooth; Alexa app, Echo voice readouts and routines | Mains USB only — no battery, so it stops in a power cut | £69.99 at Amazon as of 5 Nov 2026, 22:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The only monitor here with a carbon monoxide sensor, which makes it the one most easily misread as a safety device. Amazon's own documentation states it is not certified as a CO alarm or detector and is not a substitute for one, and its stated CO accuracy of ±5 ppm or ±30% with a baseline offset under ±10 ppm means it may register nothing at the low, sustained levels a certified EN 50291 alarm exists to catch. As a cheap PM2.5 and VOC-trend sensor for an Alexa home it is fine; it measures no CO2 at all. Best for Particulate readings in an Alexa household, at a price that regularly drops a long way below list. Good
Worth knowing
Who shouldn't buy it: Don't buy it if you are buying it for carbon monoxide protection — that job needs a dedicated alarm certified to EN 50291, which this does not replace. Read the full review → | |||||
 VOCs, temp, humidity, calculated mould risk. No radon, CO2, PM2.5, CO. · No screen — wave your hand for a red/yellow/green glow · Bluetooth to app; SmartLink needs a View-series hub (extra) · 3x AA — over 2 years claimed, over 3 years via SmartLink A damp-prone bathroom, utility room or bedroom where humidity and airborne chemicals are the actual question. | VOCs, temp, humidity, calculated mould risk. No radon, CO2, PM2.5, CO. | No screen — wave your hand for a red/yellow/green glow | Bluetooth to app; SmartLink needs a View-series hub (extra) | 3x AA — over 2 years claimed, over 3 years via SmartLink | £68 at Amazon as of 5 Nov 2026, 22:07 GMT · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched This is a VOC-and-damp device rather than an air quality monitor in the general sense: no radon, no CO2, no particulates and emphatically no carbon monoxide. Its Mould Risk Indicator is a 0–10 score calculated from temperature and humidity, not a measurement of mould or spores. It is the cheapest way into the Airthings app, but you are paying close to Aranet4 money for considerably less sensing. Best for A damp-prone bathroom, utility room or bedroom where humidity and airborne chemicals are the actual question. Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want to know when to open a window — the Aranet4 Home measures CO2 and this does not. Read the full review → | |||||
ⓘ As an Amazon Associate, PreparedBritain earns from qualifying purchases. We may earn a commission when you buy, or a fee when you request a quote, through our links. When two products are close, commission can decide which one we pick. A clearly better product always wins. Amazon prices come from Amazon's own product data and show the date and time they were retrieved. Prices at other retailers are checked by us, less often. Prices and stock can change at any time, so always check the retailer's price before you buy.
Before you buy
Start with the reading you would actually act on, because "air quality monitor" covers devices that measure entirely different things.
Carbon dioxide (CO2) is a proxy for ventilation — it climbs when people are breathing in a room that is not getting fresh air, and falls when you open a window. Particulate matter (PM2.5) covers the fine particles thrown out by cooking, wood burners, candles and nearby traffic. VOCs are airborne chemicals from cleaning products, paint and new furnishings, and most consumer devices report them as a rough trend rather than a precise figure. Radon is a naturally occurring radioactive gas that matters in specific parts of the UK. Almost nothing at consumer prices covers all four well, so pick the one or two readings that would genuinely change what you do, and buy the device that measures those properly.
The most consequential confusion in this category is CO2 versus CO.
Carbon dioxide is what you breathe out, and it is what a ventilation monitor tracks. Carbon monoxide is a different, odourless gas produced by fuel-burning appliances, and it is potentially fatal. A device that measures one tells you nothing whatsoever about the other. Of the six monitors compared here, only the Amazon Smart Air Quality Monitor senses carbon monoxide at all — and Amazon's own customer documentation states it is not certified as a CO alarm or CO detector and is not a substitute for one. Its stated CO accuracy is ±5 ppm or ±30%, with a sensor baseline offset of under ±10 ppm, which in practice means it may register nothing at the low, sustained concentrations a certified EN 50291 alarm is specifically designed to catch. Whatever you buy from this page, a separate alarm marked EN 50291 is the thing that actually protects the household.
Read accuracy claims carefully, and be sceptical of badges that sound like credentials but are not.
Aranet publishes an accuracy figure of ±(30 ppm + 3% of reading) for the NDIR CO2 sensor in the Aranet4 Home — that is a manufacturer specification rather than an independently certified one, and it should be read as the former. Elsewhere in this cluster you will meet "Calm Tech Certified" on the Airthings View Plus, which is a design accreditation concerned with how a device competes for your attention; ISO 27001, which Airthings holds as a company and which is an information-security management standard; and Apple Home compatibility on the Netatmo, which is a platform interoperability feature. None of the three says anything at all about measurement accuracy or safety. Allow for settling time too: Airthings states its CO2 and VOC readings need roughly seven days to stabilise, so treat the first week's numbers as the device finding its feet rather than as data to act on.
Radon deserves a calm, factual paragraph rather than an alarming one.
It is a naturally occurring gas whose levels vary by geology, and UKHSA and GOV.UK publish radon-affected-area maps alongside testing guidance — that is the authority to consult if you are in an affected postcode. A consumer monitor such as the Airthings View Plus or Wave Plus gives an indicative continuous reading, which is genuinely useful for seeing how levels shift with the seasons and with ventilation, but it is not a substitute for a professional radon test. After that it comes down to practicalities, and those decide whether a monitor gets used at all. A screen means you glance at it in passing; app-only means you check it when you remember. Battery models keep reading during a power cut, while the mains-powered Netatmo and Amazon units simply stop. And Airthings' cheaper Wave models need a separate SmartLink hub, or a View-series monitor acting as one, before you get continuous remote access — which makes the real cost of ownership higher than the shelf price suggests.
We verify every product's specifications against at least two independent sources, re-check its UK price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labelled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test. When two products are close, commission can decide which one we pick. A clearly better product always wins. Read our full methodology →
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Common questions
Does an air quality monitor detect carbon monoxide?
Almost never, and never reliably enough to depend on. Five of the six monitors compared here have no carbon monoxide sensor at all — they measure CO2, particulates, VOCs or radon instead. The Amazon Smart Air Quality Monitor does include a CO sensor, but Amazon states it is not certified as a CO alarm or detector and is not a substitute for one. Every home with a fuel-burning appliance needs a dedicated alarm marked EN 50291, whatever monitor is also sitting in the room.
What is the difference between CO2 and CO?
Carbon dioxide (CO2) is what you breathe out. It builds up in unventilated rooms and is a good proxy for whether fresh air is getting in — high readings mean open a window, not evacuate. Carbon monoxide (CO) is a different gas, odourless and produced by fuel-burning appliances, and it is potentially fatal. They are one character apart in writing and nothing alike in practice: a CO2 monitor gives no warning of carbon monoxide.
Which monitor should I get if I just want to know when to open a window?
The Aranet4 Home. CO2 is the reading that answers that question, and the Aranet4 does it with a manufacturer-stated NDIR accuracy of ±(30 ppm + 3% of reading) on a large-digit display you can read from across the room. The Netatmo Smart Indoor Air Quality Monitor is the cheaper CO2 option if you are happy checking a phone app rather than glancing at a screen.
Do I need a monitor that measures radon?
It depends where you live. Radon levels vary by geology, and UKHSA and GOV.UK publish radon-affected-area maps and testing guidance — check those first. If you are in an affected area, a professional radon test is the proper way to establish your levels. A consumer monitor such as the Airthings View Plus or Wave Plus gives an indicative continuous reading that is useful for tracking how levels move with the seasons and with ventilation, but it does not replace that test.
Do these keep working in a power cut?
The battery-powered ones do. The Airthings models run on AA cells — six in the View Plus, two in the Wave Plus, three in the Wave Mini — and the Aranet4 Home uses two AAs, so all four carry on reading. The Netatmo and the Amazon monitor are mains-only via USB with no battery, so they stop the moment the power does. Bear in mind that the Wi-Fi models also lose their app connection when the router goes down, even if the device itself is still running on batteries.
Do I need Wi-Fi, or is Bluetooth enough?
Bluetooth is enough if you only want to read the device when you are stood near it — that is how the Aranet4 Home works, and it has no Wi-Fi at all. Wi-Fi matters if you want remote checking, cloud history or alerts while you are out; the Airthings View Plus, the Netatmo and the Amazon monitor all have it built in. The Airthings Wave Plus and Wave Mini sit awkwardly in between: both need a separate SmartLink hub, or a View-series monitor acting as one, before they will sync continuously, and that is an additional purchase.
Will a monitor help with asthma, allergies or damp?
A monitor measures conditions, it does not treat anything, and no device here should be understood as managing or preventing a medical condition — Netatmo's "Asthmatic", "Baby" and "Family" app profiles are adjustable alert thresholds and nothing more. What a monitor can do is show you the conditions you are living in so you can change them: ventilate when CO2 climbs, run the extractor when humidity stays high, work out what is producing particulates. The Airthings Wave Mini's Mould Risk Indicator is a 0–10 score calculated from temperature and humidity rather than a mould or spore measurement, but it is a fair prompt to deal with a damp room.
