Good quality sleep is linked to health, mental wellbeing and even avoiding serious long-term ilnesses, so using a sleep monitor to check you’re getting enough rest is a no-brainer.
Wellness isn’t just about doing cat yoga and drinking alt-milks, sometimes you just need a refreshing sleep.
There are now plenty of different ways to track sleep, whether that’s through a bedside monitor, a wrist-worn wearable like a smartwatch or a device that fits under your mattress.
All will give slightly different insights and personalized tips on how to improve your rest time, but the options from our picks below are worth exploring if you want to know exactly how you’re sleeping – and making positve steps to improving it.
We’ll be breaking down what to look for in a sleep tracker, how it manages to track your sleep accurately and the best sleep gadgets to buy – we’ve tested them all so you don’t have to.
Sleep tracking: Terminology explained
Before you can pick the right sleep monitor to watch over your night, you need to know exactly what you want from one. The tech involved here is much more advanced than the smartphone apps that use the accelerometer to track movement under your pillow – and, as a result, things are much more accurate.
HR vs movement sensors
Older fitness trackers used wrist movement to track sleep, but now it’s all about heart rate monitoring – and companies like Fitbit and Withings are looking at your bpm during sleep to make assumptions not only about duration, but the sleep stage you’re in.
That means logging the amounts of light, deep, REM and awake time. You should cycle through these stages to feel rested, and if you’re not, it’s worth investigating. Pretty much all sleep trackers offer this data now, but you’ll want to know it’s estimated via heart rate, not just the motion of your arm.
A lot of devices make sleep tracking quite complicated – and when you’ve looked at the data for a few weeks you’ll start wondering what it all means.
A lot of brands now distill your data down into a meaningful number, so you can see how your slumber stacks up. Pretty much all the brands below (Fitbit, Garmin, Withings and Xiaomi) offer a single sleep score from their data.
Blood oxygen and sleep apnea
The latest data in town is blood oxygen – which is tracked using an SpO2 sensor. You’ll find them on some Fitbit, Garmin and Withings devices.
That might sound nuts, but the oxygen in your blood – or at least a dip in levels while asleep – links to a condition called sleep apnea. It’s estimated 22 million Americans suffer with it, and the majority don’t actually realise it.
Choosing a sleep tracking wearable with an SpO2 sensor will offer up this data, so you can ensure you’re not an unwitting statistic.
The best sleep trackers
Fitbit Versa 2
When it comes to tech, the Fitbit Versa 2 is the best wearable sleep tracker on the market right now.
It’s light on the wrist – just 38g – and won’t get in your way, thanks to that 40mm case size. Even better, it uses the same sleep tracking technology as the rest of the Fitbit line.
Fitbit Sleep Stages are on board, meaning you can get a daily look at your light, deep, REM and awake times, and you can still check in on how your night compares to the last month and other people your age.
(The Fitbit app shows sleep history, stage breakdowns and detailed graphs)
The Versa 2 is built with the tri-wavelength sensor on board, and uses a relative SpO2 sensor to unlock Estimated Oxygen Variation while you sleep. This is a measure of the oxygen in your blood, and large swings can be a sign of disorders like sleep apnea.
Also keep an eye out for Sleep Score, which helps you to interpret sleep data. It melds your sleep duration, restoration, heart rate data, blood oxygen and time tossing and turning into one easy-to-understand score.
And if all that’s not enough, Fitbit has even added a new feature that will tell you if you snore.
Price when reviewed: $199.95
Wareable verdict: Fitbit Versa 2 review
While a smart ring may be not be the first device you’d think of, the Oura ring is a powerful and discreet sleep tracker that’s well worth serious consideration.
It’s packed with sensors including optical heart rate, accelerometer, gyroscope and body temperature sensors. This gives it unique insights into your sleep that rivals in this list can’t offer, and it’s all geared to two main areas: readiness and sleep.
Based on your sleep score, Oura provides you with a simple, intuitive readiness score for the day. That’s based on more than just sleep, including heart rate variability and activity data too. It’s one of the most complete biometric trackers out there, and has been in trials for Covid-19 detection.
Oura comes in two models and ring sizes US6 – US13. In its second iteration, this smart ring is significantly slimmer and sleeker than its predecessor.
Wareable verdict: Oura Ring 2018 review
Price when reviewed:From $299
The Withings Sleep slips under your mattress and collects your sleep data, and was recently released back under the company’s name after the buy-back.
It’s not the latest version – the Withings Sleep Analyzer has landed in Europe, but hasn’t received FCC approval for its main sleep apnea feature. So if you’re in the US, the Withings Sleep is the only option for the forseeable.
The Withings Sleep able to collect data like sleep duration, interruptions, light, deep and REM sleep, plus snoring, thanks to a built-in microphone.
It can tap into the Withings app, giving you a coaching program to help reduce fatigue and improve health. A big new feature addition is that it now has the ability to detect the signs of sleep apnea.
There’s not a lot to pick between the sleep mat and Fitbit’s wrist-based options in our testing – but we did have some accuracy issues around waking up but staying in bed.
Sleep score is a major focus, as it is on most tracking apps now. It’s the most obvious way to find out whether you had a good night’s sleep, and will be in red if you had a bad night. The higher the score, the better night of sleep you had.
Even better, the app helps you understand what makes a good night of sleep by telling you how to raise your Sleep Score.
We are still putting the Withings Sleep through its paces, but we have tested the Nokia Sleep, which, as we say, is the same device with the Nokia name on the front of it.
If you want to an idea of what the Withings Sleep is going to be like to use, definitely go have a read of our Withings Sleep Analyzer review.
Price when reviewed: $99.95
Fitbit Charge 4
The Charge 4 also offers the best of the Fitbit sleep tracking experience – and has the same feature set as the Versa 2, including SpO2 blood oxygen monitoring. The only real difference is the form factor.
You get Fitbit Sleep Stages, giving you a more in-depth look at your sleep. It’ll track whether you’re in light, deep or REM sleep, giving you actionable insights the next morning.
Plus, you can compare your results against people of a similar demographic, as well as your average night’s sleep over the past 30 days.
What we like about Fitbit’s sleep tracking is that it learns your behaviour over time, and will start giving you more and more personalised feedback for getting better rest.
(Fitbit provides sleep overviews, sleep stage breakdowns and a graph)
Tracking accuracy is as good as it gets from the wrist, and the intuitive companion app, where the sleep graphs are held, completes a package that makes this the best fitness tracker for sleep.
Price when reviewed: $149.99
Wareable verdict: Fitbit Charge 4 review
Garmin Vivosmart 4
The diminutive Vivosmart 4 may look like a basic tracker – but it’s actually packed with sensors that can deliver serious insights – and some of the best are around sleep.
Garmin’s sleep reporting has got a lot better in the last year, with in-depth looks at sleep cycles – and the duration within each zone. This simply wasn’t part of the app before. The Vivosmart 4 has a heart rate sensor, and leverages that data to offer insights on sleep cycles.
The Vivosmart 4 also boasts a SpO2 and will track blood oxygen levels in the app, which are read while you’re asleep. That means it’s capable of highlighting sleep apnea, if you pay attention to the data.
if you are struggling to drop off, there’s guided breathing exercises built into the device and stress tracking – which you can correlate against poor sleep to try and make positive changes.
It’s not all about sleep – the Vivosmart 4 will offer VO2 Max data if you use it for workout tracking.
The only reason we’re not all-out recommending the Vivosmart 4 is because we feel the Garmin Connect app experience still lags the Fitbit one – with an overload of data, and less insights. But we love the Vivosmart 4’s design coupled with top quality tracking data.
Price when reviewed: $129.99
Wareable verdict: Garmin Vivosmart 4 review
Whoop Strap 3.0
The Whoop Strap 3.0 is a completely different proposition. First and foremost it’s a workout tracker, which can be worn in multiple locations and the choice of CrossFitters and functional fitness types for tracking hardcore sessions.
But while you can read about those aspects in our best gym trackers round up, sleep racking is a huge part of the Whoop Strap 3.0’s make-up.
A bit like Oura, the Whoop Strap 3.0 will assign a sleep quality score based on the duration of your sleep measured against your prescribed ‘sleep need’ which is based on training and your rest across the week.
It also does the usual stuff: sleep stages such as REM and deep sleep.
And you can also factor in things like caffeinated or alcoholic drinks, screen time or whether you shared your bed.
This is all used to advise you when to train, and when to take a day off. This is presented with a single number – Strain Score.
Of course, this isn’t a band for those looking to take a few more daily steps (it doesn’t actually track steps at all) – but for seasoned gym-goers it’s the best option on offer.
But it costs more than your average Fitbit. There’s a $25 per month subscription, with a minimum term of six months – but you do get the Whoop Strap 3.0 for free.
Read our full Whoop Strap 3.0 review.
Withings Steel HR Sport
The first watch back under the Withings brand is also one that’s able to track your sleep, with the Steel HR Sport providing awake, light and deep sleep times, as well as giving you a look at how your heart rate varies through the night. There’s much better sleep insights coming on the Withings ScanWatch – but we’ll reserve judgment until out full review lands.
Unless you’re someone who hates having anything on their wrist in bed, the Steel HR Sport’s slim physique makes it comfortable to wear to sleep. There’s an alarm as well, so you can be woken by a gentle vibration on your wrist, instead of a blaring noise.
In our testing, accuracy wasn’t perfect, but not terribly far from Fitbit’s standard. The data is easy to digest, as shown above, but sadly the insights aren’t quite as meaty as we’d like. However, if you’re looking for something that’s good at the basics when it comes to sleep, the Steel HR Sport is by no means a bad call.
Price when reviewed: $199.95
Wareable verdict: Withings Steel HR Sport review
Xiaomi Mi Band 4
Xiaomi has been cracking out some really impressive fitness trackers for low prices in recent years, and its latest, the Mi Band 4, is a real gem. For roughly $40, you get a full range of tracking, including entirely capable sleep tracking.
The Mi Band 4 records sleep duration and gives you a sleep score, as well as some sleep quality analysis. This might mean it telling you to go to sleep earlier or acknowledging that your deep sleep was short. You’ll even get sleep regularity insights, giving you a sense of your average sleep data over the last week in comparison to other Mi Band 4 users.
But, importantly, that data is presented clearly and digestibly on Xiaomi’s companion app. You can see your trends, and look at individual nights’ data if preferred. It’s also accurate – sleeping with the Mi Band 4 and other trackers produced similar readings. For the price, and given its comfortable, lightweight body and 20-day battery life, the Mi Band 4 is a seriously persuasive option as a sleep tracker.
Price when reviewed: $40
Wareable verdict: Xiaomi Mi Band 4 review
Apple Watch Series 3/5
We’ll throw in a major caveat at the start: the Apple Watch cannot track sleep – at least not through the company’s own means.
However, it makes the cut because of the sheer breadth of third-party apps and it makes no difference whether you choose the newer Series 5 or the cheaper Series 3 – which we’ve highlighted here.
We’ve tested the best Apple Watch sleep tracker apps (yes, there really are that many), and all will give you slightly different results and experiences, but they’re all harnessing the same sensors to try bring you a look at your night’s sleep.
We personally recommend Pillow, which has an annual subscription for the best bits, or AutoSleep, which costs $2.99.
Accuracy isn’t quite as good as Fitbit or a dedicated sleep tracker, and the single day battery life means you’ll have to charge the smartwatch in the day if you want it to be working in the night, which can be a little challenging.
It’s also a comfortable smartwatch to wear to bed. Again, not quite as light or small as the Fitbit options – even if you get the 38/40 mm variation – but not a device that feels alien to keep on. And that’s especially true if you’re wearing a light band, such as the sporty silicon or knitted loops.
And then there’s also everything else to consider with buying an Apple Watch – this is comfortably the best overall smartwatch you can buy in 2019. And even if native tracking isn’t available now, there has been recent speculation that an Apple Watch with built-in sleep tracking is in the works.
Price when reviewed: $199.99
Wareable verdict: Apple Watch Series 3 review
Fitbit Inspire HR
A third and final entry for Fitbit, we’ve added the Inspire HR because it’s a powerful sleep tracker but it’s thin and light design make it so comfortable to wear to bed.
You get the full sleep tracking experience, with sleep stages, restoration, heart rate and sleep score all provided – but you don’t get Estimated Blood Oxygen Variation because there’s no SpO2 on board.
Elsewhere it’s the same top-notch Fitbit experience – just in a smaller, thinner and cheaper package.
Check out our Inspire HR review
Beddit 3.5 Sleep Monitor
Apple owned Beddit is one for iOS users that really want to get focused on sleep insights. It tracks sleep time, heart rate, breathing, snoring, and bedroom temperature and humidity.
It does this from under the mattress, using a 2mm thick sensor – so there’s nothing to wear, and can’t be detected.
The ability to track ambient conditions is one big benefit of Beddit over wearables, and things the temperature can really affect how restful your sleep can be.
You get weekly reports on your sleep, and it works with the Apple Watch to nudge you when it’s time for bed.
The Beddit 3.5 is a good system, but it’s a couple of years old now. We’d certainly recommend the Withings Sleep Analyzer (or Withings Sleep in the US).
Price when reviewed: $149.99