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The best pulse oximeter in 2021

best pulse oximeter
(Image credit: Getty Images)

Looking for the best pulse oximeter? This guide is here to help you choose the right one - and help show you the best price you can get it for.

Home pulse oximeters are a great tool for keeping on top of your blood-oxygen levels – and are now highly affordable. If your home medical kit consists of nothing more than sticking plasters and antiseptic, you might be surprised such a thing is even possible. For many, though, it is very desirable to monitor blood oxygen saturation (SpO2), a figure which can reveal illness even when the patient isn’t aware of it – and something to add to your medicine cupboard alongside the infrared thermometer.

Blood should have an SpO2 of 95-100%. Below 90% is dangerously low and called hypoxemia. A pulse oximeter works a bit like a digital camera, as SpO2 can be detected optically by passing light from an emitter to a sensor somewhere arterial blood is flowing (like the middle finger of the dominant hand). The higher the oxygenation, the fewer light frequencies pass through. The devices also have to compensate for the distance the light is traveling and any ambient light for accurate results.

Certain conditions require regular monitoring, while athletes and pilots can all benefit from having their own devices. In a time when acute respiratory diseases are rampant (SARS, Covid-19) anyone might be able to detect a drop in lung capacity by taking regular readings, though of course you can only help your doctor, not replace them!

(Image credit: Atmoko)

1. Atmoko OLED Pulse Oximeter

Best pulse oximeter overall with clear display

Dimensions: 61x37x33mm (2.4 x 1.5 x 1.3 in) | Power: 2xAAA | Reading: 10sec | SpO2 Accuracy: ± 2% | Pulse accuracy: ± 2bpm

High quality multi-angle OLED display
Simple to use on self or others
Easy to operate
Batteries not rechargeable

This is a classic finger clip design with a dark skin-friendly silicone coating inside the clip and a single button to operate. The readout is a pleasing 2-tone OLED display (yellow and cyan), which is a little friendlier than 7-segment LEDs seen on some, and also allows for the nifty trick of being viewed from any side, automatically and without menu fiddling (a gyro handles it) and showing a pulse waveform. That means you can hold your finger up to see your own read out, but if you’re checking your friend or parent just ask them to rest their finger and the number will appear the right way up to you. The only other ‘function’ is a long-press of the power button, which cycles through five steps of brightness. Obviously this design isn’t suitable for wearing during an activity, but you can pop it on as you reach that mountain summit. 

Best pulse oximeter - Zacurate Pro CMS500 series

(Image credit: Zacurate)

2. Zacurate Pro Series 500DL

Best budget pulse oximeter

Dimensions: 59x37x33mm (2.3 x 1.5 x 1.3 in) | Power: 2xAAA | Reading: 10sec | SpO2 Accuracy: ± 2% | Pulse accuracy: ± 1bpm

Simple to use
Easy to read screen
Suitable for children over 12
Choice of colors
Batteries not rechargeable

Zacurate’s 500DL is not their first finger pulse oximeter designed for the home market, so they’ve had the chance to address a few issues, not least that the predecessor could only display up to 99% rather than the 100% maximum SpO2. Carrying CE & FDA approval, this device can produce a reading to its large, clear display in 10 seconds, and (according to the manufacturer) is less susceptible to inaccuracies if slightly moved and has better ambient light compensation. The 500DL is intended for adults but can read any fingers large enough, so kids over 12 should be fine. There is no memory, but the batteries should be good for 40 hours worth of reading so even with the ten seconds it takes to shut down after use that one set of AAAs will last a while!

(Image credit: Wellue)

3. Wellue o2Ring

Best pulse oximeter for extended monitoring

Ring diameter: 50-82mm | Weight: 15g | Power: | Water resistance: IP24 | Compatibility: iOS 9+, Android 5+, Windows 7/8/10, MacOS 10.5+

Smartphone synchronization
Ideal for long-term monitoring

On the face of it, this is a slightly chunky (3.8cm/1.5in) black polished thumb-ring. A second glance shows you it’s no piece of jewellery though – the discrete built in display giving the game away. Inside the dark pebble is a rechargeable battery providing up to 16 hours of recording, at 1s intervals, of blood oxygen, pluse (BPM), and motion. All your data can be synced over Bluetooth 4 to your App or desktop (the latter offering printing or PDF export). The ring can also be set to vibrate should it drop below the level of your choice. Marketed as an alternative for wrist-worn alternatives, this certainly seems more convenient, though the outlay is considerably more than a simple ‘dumb’ finger measure, but if you’re monitoring your sleep this is an excellent choice (you can also use it without removing nail varnish too, if that’s important to you!).

(Image credit: Apple)

4. Apple Watch 6

Best smart watch with pulse oximeter

Face diameter: 44mm | Weight: 30.5g | Power: Rechargeable | Compatibility: iOS

The best Apple Watch yet
Choice of aluminum, stainless steel, and titanium 
Huge choice of colors and strap styles
Expensive if you are just after pulse oximeter!
You need an iPhone to use many of the features

The latest and best-ever Apple Watch has health at the forefront of its new features. A new sleep app uses motion sensors to measure how you sleep. With personal hygiene being more in our mind than ever before, it will use a motion sensor to time how long wash your hands. And most significantly it adds a pulse oximeter for the first time, using a cluster of four IR LEDs that take a SpO2 measurement in just 15 seconds, and that can monitor the values 24/7. The new Watch OS 7 also makes sure that the VO2 Max values can be used by a range of apps – and you can even get a notification if your VO2 Max drops to lower levels. Of course, there is plenty of other features available with this GPS-enabled watch, enabled by its ever increasing range of optional apps.

(Image credit: Garmin)

5. Garmin Vivoactive 4

Best budget smart watch with pulse oximeter

Face diameter: 45mm | Weight: 50g | Power: Rechargeable | Compatibility: iOS, Android

A great smart watch
Round face design
Not medical grade

Monitoring blood-oxygen levels is useful for athletes, especially mountaineers who have to be sure they’re coping with dropping oxygen levels at altitude. While the Garmin’s built in monitor is not medical grade, it can certainly help provide an insight, and of course is complemented by heart rate, body energy, hydration, sleep and stress monitoring among others. The watch also boasts GPS and coaching features to help you train, as well as contactless payments and a music player (if you provide compatible headphones). All that is before you pair with a smart phone for notifications and more, making this a very handy way to keep yourself moving in places you wouldn’t take your phone though, so if you’re thinking of getting a smart watch and want to follow blood oxygen then, yes, this doesn’t claim to be medical quality, but it’s still a feature many more expensive smart watches lack (though Apple has at last caught up with this). This version has a 45mm face, but there is a smaller Garmin Vivoactive 4S version with a 40mm face too.

(Image credit: Hermano)

6. Hermano Baby & Children Digital Fingertip Pulse Oximeter

Best pulse oximeter for kids

Dimensions: 44x26x33mm (1.734 x 1.04 x 1.3 in) | Power: Rechargeable battery | Reading: 10sec | SpO2 Accuracy: ± 2% | Pulse accuracy: ± 2bpm

Child-friendly design
Ages 1-12
Cute design won't fool cynical kids

Whether featuring a playful design will fool the kids into thinking this is not a medical device is open to debate. My 4 year old never fell for the sweet taste in kids medicines, and would see right through this. So the styling is never going to make your kids sit still for ten seconds, but it’s still handy to take readings from children from 1 to 12 years (other kids fingertip devices only work from 2 years). Larger ‘adult’ fingertip readers can produce incorrect results if they don’t grip the finger properly, so if your kids are your concern your choices are limited. The 200mAh lithium battery and Type-C USB recharge connector does make rival AAA-powered devices seem a bit ‘old tech’, but there is a bump in price which can’t just be explained by the cartoon penguin/bird.

(Image credit: Owlet)

7. Owlet Smart Sock 2

Best pulse oximeter for babies

Base station dimensions: 88mm diameter, 17mm height | Power: Mains power (base station) | Communication: Bluetooth (to base station) & Wi-Fi | Compatibility: iOS 12+ and Android 5+

Elegant design
More comfortable than arm bands
Ages 0-18 months
Only suitable for babies up to 25lb

Some parents will baulk at the cost of a device with an 18-month lifespan (once your baby hits 25lbs or 11kg, they’ve outgrown it), but for nervous first-time parents this product can provide significant peace of mind, and makes it possible to move the baby into its own room sooner. The ‘sock’ (there are three in the box, washable, and of increasing size), sends data from its pulse oximeter to a base station via Bluetooth and, if all is within parameters, the flat puck like base station glows a reassuring green. If there is cause for alarm it’ll turn red and you’ll be notified by and alarm and by your smart phone. A nice touch is that a yellow warning just plays a nursery rhyme, before going the whole red, but given the price of this device, it might only really make sense for those whose pediatricians have detected specific concerns like apnea. It’s also wise to buy from a trusted store that will accept returns if the baby’s skin reacts badly to the sock.

(Image credit: Garmin)

9. Garmin Enduro

Best adventure-grade sport-watch with pulse ox

Face diameter: 51mm | Weight: 61g (Titanium) or 71g (Steel) | Power: Solar-charged battery | Compatibility: iOS, Android

Sports watch
Solar powered
Not medical grade

Garmin’s pulse oximeter makes a great deal of sense on a solidly-built watch like this since it can be used to determine how your body is acclimatizing to an upcoming challenge like altitude. Because of the battery life, the pulse oximeter can optionally be used all day and for sleep monitoring. The information is combined with heart rate data to help track your sleep and keep an eye on your stress. Not only that, but the watch is equipped with an array of other tech to help you push your body (and get adequate rest times). Apple Watch owners will be envious of the up-to 80 hours which this device can keep going for, topping itself up via solar energy (if you’re lucky enough to be training in good sunlight for about 3 hours. The  Enduro has a distinct look, so won’t be for everyone, but the always-on screen and solid design is ideal for sports fanatics.

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Adam is Digital Camera World's resident drone expert. He is the author of a number of books including The Complete Guide to Drones, The Smart Smart Home Handbook, 101 Tips for DSLR Video, and The Drone Pilot's Handbook.