A sleep tracker is a device that monitors the duration and quality of your sleep. Many times, this technology is integrated into Fitbits or other fitness trackers, but not always—there are dedicated sleep trackers that you only have to wear at night. Thanks to advances in wearable technology, sleep trackers are compact, lightweight, and easy to use.
They can give you valuable feedback on not just how much sleep you are getting, but also crucial data on your sleep quality: how much you toss and turn, whether you wake up in the middle of the night, and (in some models), physiological parameters like your heart rate, blood oxygenation level, and heart rate variability.
Sleep trackers are great if you want to find out whether you’re truly getting high quality sleep, or if you want hard data on how much you are actually sleeping.
There’s a lot of variation from device to device in terms of usage, number of features, and quality, so we had our research team take a look at the options on the market to identify the best sleep trackers of the year.
The big picture
Sleep trackers help you monitor how many hours per night you sleep, the overall quality of your sleep, and sometimes, your heart rate and blood oxygen levels.
Sleep trackers are great both for fitness enthusiasts who want to make sure they’re getting enough recovery and for people who want to determine whether they’re tossing and turning or waking up in the middle of the night.
As of right now, the Garmin Vivosmart 4 is the top sleep tracker on the market, thanks to its insightful sleep metrics and its ability to directly measure blood oxygenation throughout the night.
1. Garmin Vivosmart 4
The Garmin Vivosmart 4 is one of the few sleep trackers from an industry-leading brand that actually gives you raw blood oxygenation data, which alone makes it an excellent pick. Garmin’s activity recognition capabilities have improved by leaps and bounds recently, and its heart rate tracking is excellent too.
Why we like it: Garmin is known for providing accurate data, so the Vivosmart 4 is one of the most trustworthy devices that provide SpO2 (blood oxygenation) data. Garmin’s new advanced sleep tracking algorithms have markedly improved the quality and amount of sleep data you get, too.
Flaws: If you don’t like devices on your wrist, you may need to opt for a mattress-based or ring style sleep tracker instead.
2. Withings Sleep Tracker
Withings makes one of the best mattress-based sleep trackers. Slip this under your mattress and you’ll get detailed feedback on your sleep quality. You can even connect it to smart home apps to automatically turn off the lights when you get into bed.
Why we like it: If you can’t stand anything on your wrist or finger when you go to bed, a mattress-based sleep tracker is the way to go. Withings offers nice app functionality and installation is super easy.
Flaws: Though Withings attempts to detect abrupt awakenings from sleep apnea, its lack of blood oxygen data seriously hampers its utility for people with sleep apnea. It can track tossing and turning, and it’s great at determining when you go to bed and when you get up in the morning, though.
3. Wellue O2Ring Oxygen Tracker
Wellue is a ring style sleep tracker that is specifically designed to monitor oxygen levels. If you don’t like wrist worn device and want to get SpO2 data, it’s your best bet.
Why we like it: Wellue does one thing and does it well. Your blood oxygen data get transmitted to an app where you can easily review your night’s sleep.
You’ll see several metrics, including your average blood oxygenation, lowest level, your heart rate, and the duration of time you spend below 90% blood oxygenation. If you want deep insights into the minute by minute trends of your blood oxygen, it’s a great tool.
Flaws: The device itself is a bit clunky, and it has a few features that aren’t very useful for sleep tracking. For example, it displays your blood O2 level on the screen in real-time, and you can set vibration alerts if your blood oxygen level dips below a certain level—but of course neither of these are particularly useful if you are asleep.
4. Fitbit Charge 3
If you are looking for a sleep tracker that doubles as a fitness tracker during the day, the Fitbit Charge 3 is hard to beat. With great sleep metrics and equally good daytime utility, it’s our number one pick.
Why we like it: Fitbit’s sleep detection technology performs quite well, and the newest version of the Charge will soon support SpO2 sensing which can measure your blood oxygen levels. Its app has great cross-platform support and could hardly be easier to use.
Flaws: The only people who may struggle with using the Fitbit Charge 3 as a sleep tracker are those who are bothered by wearing anything on their wrist when they go to bed—if that sounds like you, opt for a mattress-based sleep tracker instead. The SpO2 tracking hasn’t been enabled in software just yet, though it’s rumored to be coming soon.
5. Motiv Ring Tracker
Motiv looks like the future of activity tracking: this tiny ring counts steps, tracks your heart rate, and estimates the quality of your sleep.
Why we like it: If you want a device that’s discreet and compact, Motiv is the best pick. It’s hard to believe how Motiv fits all the sensors into such a small package, but the end result is pretty impressive
Flaws: Since Motiv isn’t one of the big players in fitness trackers, their app functionality and the accuracy of their sleep and activity tracking is not the best. One sensor it is missing is an SpO2 monitor: you won’t be able to track your
6. Akasma Fitness Tracker HR
Akasma makes a basic and very popular fitness tracker that doubles as a sleep tracker. If you want a simple device that does fitness and sleep tracking, it’s a solid option.
Why we like it: Tracking sleep, counting steps, and monitoring your heart rate has never been easier. This device is super easy to use, and gives you all the basic data you need.
Flaws: Without an SpO2 sensor, you don’t get blood oxygenation data, and the activity recognition accuracy of this device is not as good as a device from one of the bigger companies in the market. Still, if all you want is some accountability on your nightly hours of sleep, Akasma is a good way to go.
7. Fitbit Versa 2
Top manufacturers have figured out that many people want lots of features all in one wearable device—hence, the rising popularity of smartwatches. The Fitbit Versa 2 is a jack of all trades, but still manages to do a great job at tracking sleep and surprisingly good accuracy at identifying sleep.
Why we like it: People who care about their sleep tend to care about physical activity, exercise, and calorie balance as well. The Fitbit Versa 2 does a great job of measuring all of these, without sacrificing much on the sleep tracking front.
Flaws: Though the Versa 2 has an oxygen sensor, you can’t access the raw data just yet—rumor has it Fitbit is working with the FDA to get the Versa 2 approved for detecting sleep apnea, and until then the SpO2 data is only used to calculate the sleep score metric; you can’t see the raw numbers just yet.
8. Polar Ignite
Polar is an industry leader in heart rate monitoring technology, so it’s not surprising that they’ve added sleep tracking functionality to their flagship smartwatch.
If you want a sleep tracker that does a great job at tracking heart rate and heart rate variability, this is the best option on the market.
Why we like it: Polar has long been known to be the most accurate brand in heart rate monitoring, and this watch’s ability to double as a fitness tracker and heart rate monitor make it a good pick for athletes.
Flaws: Surprisingly, the Polar Ignite doesn’t do blood oxygenation levels—though the number of serious athletes who have sleep apnea is a lot smaller than the general population. Rumor has it that Polar’s devices actually have the sensors to do SpO2, but the company is still fine-tuning their data processing algorithm.
9. ViATOM Wearable Oxygen Monitor
ViATOM’s sleep tracker is big and a bit clunky, but it gets you the data you want if you care about blood oxygen levels.
Why we like it: There aren’t a whole lot of devices that give you detailed access to your blood oxygen levels throughout the night, but ViATOM is one of them. The sleep analytics are decent, but it’s the SpO2 sensing that really sells this device.
Flaws: This sleep tracker can be annoyingly big, and some of the features (like vibration alarms) aren’t particularly useful. The app is okay, but could be improved.
10. Beautyrest Sleeptracker Monitor
Beautyrest makes a mattress-based sleep monitor that uses small pads that fit under your mattress and wire into a central unit below your bed. It’s a solid pick for people who just can’t stand a wearable device at night, but don’t expect the same level of accuracy.
Why we like it: Since the sensors are under your bed, you’re not as likely to knock them over as you would be with non-wearable sleep trackers that sit on top of your mattress.
Flaws: While Beautyrest purports to track breathing and heart rate, there’s just no way to do that accurately through a thick mattress. Some users report accuracy issues if they are sitting up reading in bed: this can get counted as “light sleep.” Compared to other under-mattress devices, there are also a lot of cables and cords to manage.
Who should buy a sleep tracker?
If you are concerned about the amount or the quality of the sleep you get, a sleep tracker makes it incredibly easy to track. Before sleep trackers came around, you used to have to keep a sleep diary, and all that would tell you is when you went to bed and when you got out of bed.
If you wanted more data on the quality of your sleep, or whether you woke up during the night, you had to go to a sleep clinic. And if you wanted detailed day-by-day data, that was totally out of the question.
Sleep tracking technology has improved by leaps and bounds in recent years: now, you can get data on your heart rate, your heart rate variability, and your blood oxygenation levels, in addition to data on overall sleep quality and number of times you wake up during the night.
Sleep trackers are great for athletes who want to have accountability data on their sleep. A lack of sleep hinders performance and increases your risk for sports injuries, so keeping yourself accountable with a sleep tracker is incredibly useful for people who are serious about performance.
With a sleep tracker that monitors heart rate, you can also track resting heart rate and heart rate variability, which many performance experts believe could be used as an early warning sign for overtraining.
People with sleep apnea also find sleep trackers useful, for two reasons. First, they can track how often they wake up during the night, which can provide info on the severity of your sleep apnea and whether any treatments you are using are working.
Second, modern sleep trackers can also monitor your blood oxygenation levels, which can help you figure out how much your ability to breathe is being restricted by your sleep apnea.
Sleep apnea isn’t the only sleep disorder that can be aided by using a sleep tracker—if you have trouble falling asleep or staying asleep, a sleep tracker can help pinpoint what time of night your sleep troubles occur, and can be used as a quantitative, objective measurement of whether treatment strategies, like avoiding screens before you go to bed, are having any effect.
How we ranked
Our researchers formulated our rankings by taking stock of all of the sleep trackers available on the market, then evaluating them on their performance, features, comfort, and ease of use.
Sleep trackers can be broadly divided up into two categories: the first and most common category is wearable sleep trackers, which you put somewhere on your body before you go to bed, and mattress-based sleep trackers, which go somewhere on your mattress (often underneath it).
Some wearable sleep trackers, like Fitbits, can often double as a fitness tracker, and if you want data on your heart rate, a wearable sensor is the only way to get it.
However, some people find that wearing a wristband or a ring to bed is uncomfortable, and actually interferes with their ability to fall asleep.
While we found that wearable sleep trackers tend to offer the best features, we also made sure to include a few of the best mattress-based sleep trackers to cater to users who don’t want to wear something when they go to bed every night.
In terms of features, the ability to track sleep and wake time was non-negotiable: every tracker on our list had to make it easy to figure out how many hours of sleep you got.
Next we looked for basic features like calculating sleep cycle duration and measuring how often you toss and turn. We rewarded products that integrated heart rate monitoring, for two reasons: first, knowing your resting heart rate can tell you a lot about your body’s overall health and fitness level (a low resting heart rate protects you against heart disease, for example), and second, heart rate variability might be able to identify when you’ve been pushing yourself too hard in workouts.
Some of the best sleep trackers featured blood oxygenation as well as heart rate—these devices landed even higher in our rankings.
While it does require an extra sensor on the device, tracking blood oxygenation is a game-changer for people with sleep apnea: to get good data on how low your blood oxygen levels drop at night (not to mention how many times you wake up suddenly), you used to have to rely on sleep clinics.
Comfort was mostly applicable to wearable sleep trackers. We checked to see the range of wrist or ring sizes supported by the device and whether the sleep tracker in question used comfort-friendly design, like soft silicone bands instead of hard plastic, or hypoallergenic metals for any clasps.
Ease of use applied to all devices: we looked at how easy it was to put on and take off the device, or in the case of mattress-based sleep trackers, how simple the installation was. For all devices, app integration and functionality was critical.
The best sleep trackers have great apps with lots of features that are still easy to use, both on Apple and Android phones. We docked points for poor-quality app design or difficult to understand menus.
Finally, we sorted the remaining products based on their overall quality, as measured by our ratings on performance, features, comfort, and ease of use. The remaining sleep trackers made up our rankings of the best sleep trackers on the market right now.
Sleep trackers can detect drops in blood oxygen levels that result from sleep apnea. Obstructive sleep apnea is one of the most common sleep disorders, and is caused by obstructions to airflow in your throat.
When airflow is obstructed, your blood oxygen levels steadily decline, which eventually leads your body to briefly jolt awake and gasp for air.
These “apnea events” can happen dozens of times during the night. As these apnea events rack up, they seriously inhibit your ability to get a good night’s sleep. People who have untreated sleep apnea are at a greater risk for everything from heart disease to car accidents.
Fortunately, sleep trackers can get you hard data on whether you are having obstructive sleep apnea events at night. While a sleep tracker can’t diagnose sleep apnea as well as a full battery of testing at a sleep clinic, dips in blood oxygen level are nevertheless useful for identifying the existence and the severity of sleep apnea (1).
Sleep trackers can help dexter sleep issues. Sleep apnea is quite common—anywhere from nine to 38% of the population is thought to have at least mild sleep apnea, according to one systematic review study of the subject published in 2017 in the journal Sleep Medicine Reviews (2).
Men, older adults, and people who are overweight or obese are all at greater risk for sleep apnea, but one of the biggest problems facing people at risk for sleep apnea is not realizing that they have it.
You are asleep, after all, and the brief awakenings to gasp for air are too brief for you to consciously realize that you’ve awoken. People often go decades before they learn they have sleep apnea.
If you’ve been told that you snore, or if you never feel rested even after a full night’s sleep, you should immediately start to suspect that you have sleep apnea. A sleep tracker can help identify whether you have the dips in blood oxygenation at night that are characteristic of sleep apnea, though you’ll need to pay a visit to a sleep clinic to get a full work-up.
Sleep trackers help to evaluate sleep quality. How well you sleep affects just about everything in your waking life—your cognitive capacity, your ability to pay attention and focus, and your mood.
Thus, you’d think people would be pretty good at subjectively evaluating the quality of their own sleep—things like tossing and turning, waking up at night, or not falling asleep for a long time after going to bed.
A 2015 study in the journal Frontiers in Aging Neuroscience by a team of researchers at the University of British Columbia in Canada put this proposition to the test: they wanted to see whether peoples’ perception of their sleep quality lined up with objectively-measured sleep quality using a research-grade sleep tracker (3).
The researchers had a group of 78 adults over age 55 complete a sleep quality index questionnaire, and use a sleep tracker for the same night of sleep. The results showed that, contrary to expectations, peoples’ subjectively reported sleep quality correlates very poorly with objective metrics of tossing and turning, nighttime awakenings, and sleep duration.
These results make a good case for using a sleep tracker to get objective data on the quality of your sleep. Just like with sleep apnea, your personal perception of your sleep is not a good indicator of the true quality of your sleep.
Q: What is a sleep tracker?
A: A sleep tracker is a device that you either wear or put under (or on) your mattress that detects when you go to sleep, when you wake up, and the quality of your sleep at night.
They’re very similar to Fitbits and other fitness trackers, except for sleep instead of exercise—and indeed, many Fitbits offer sleep tracking capabilities as well. Thanks to advances in heart rate monitoring technology, top of the line sleep trackers can monitor your heart rate, heart rate variability, and blood oxygenation level.
These first two metrics are of interest to athletes, but blood oxygenation level is very useful for getting more information about possible sleep apnea. In sleep apnea, blood oxygenation levels drop because your airway becomes partially obstructed, which leads to disrupted sleep.
These repeated dips in blood oxygen level may be detectable with a sleep tracker, which can give you unprecedented data about the number and severity of sleep disruptions during the night.
Q: Can the Apple Watch be used to track sleep?
A: The Apple Watch is equipped with all of the necessary sensors to track your sleep, including a heart rate monitor and a blood oxygen sensor. Apple hasn’t released its own sleep app just yet, but there are lots of rumors about a sleep tracking app that is under development at Apple (4).
Based on the experiences of other companies, Apple is likely hung up on ensuring that the watch accurately detects when you are sleeping. They also may be trying to get the app approved by the Food and Drug Administration, like their much-praised electrocardiogram functionality.
Until that app comes out, third-party apps like SleepWatch from Bodymatters offer many of the sleep tracking features you’d expect. While the accuracy of these third-party apps is untested, many people still find them very useful.
Q: How do sleep trackers work?
A: Sleep trackers have two primary tasks: first, to detect when you are asleep, and second, to objectively monitor the quality of your sleep. Identifying when you are asleep is based on motion sensors that detect the position and the movement of the sleep tracker.
Since your arm is going to be parallel to the floor when you sleep, and your arm movement will be small (but not completely still) when you sleep, this information can be used to detect when you are asleep.
The second task is far easier: once you are asleep, motion sensors in a sleep tracker detect how often and how vigorously you toss and turn, and LED-based sensors detect your heart rate and your blood oxygenation level based on the absorption of certain colors of light in your skin.
Since oxygenated blood absorbs infrared and green light differently than deoxygenated blood, changes in light absorption can be used to track heart rate and blood oxygenation.
Q: Which Fitbits track sleep?
A: The Charge 3, Versa 2, Versa Lite, Ionic, and Inspire HR all include sleep tracking. However, the Fitbit Inspire HR does not include the ability to track blood oxygen saturation levels (SpO2), so it’s a less optimal pick than the other four if you want to use a sleep tracker to check your blood oxygenation when you are asleep.
Fitbit is reputed to have some of the best sleep tracking on the market thanks to their enormous amount of user data, so any of these Fitbits make great choices as sleep trackers.
Q: How accurate are sleep trackers?
A: Compared to the accuracy of consumer device like Fitbits and other fitness trackers, sleep trackers still have a ways to go. While activities like walking, running, and swimming can be recognized fairly well, scientific research has found that commercially available sleep trackers vary widely in their ability to track sleep.
Identifying wake time is particularly challenging: one critical review noted that wake detection accuracy varies widely among commercial devices (5). However, the challenges in identifying wake time seem to balance out with identifying when you fall asleep, such that the total amount of time you spend sleeping ends up being estimated fairly accurately.
One study published in the Journal of Psychosomatic Research reported excellent estimation of total sleep time using a commercial sleep tracker in both healthy adults and insomniacs (6).
The good news about sleep tracker accuracy is that improvements in sleep tracking come along all the time, and are driven by software improvements, not necessarily hardware improvements. So, even with the same device, you can expect the accuracy to get better over time.
Q: Are there non-wearable sleep trackers?
A: Yes, non-wearable sleep trackers are usually mattress-based devices that sit on top of or underneath your mattress, and use data from motion sensors in the device to detect when you toss and turn at night.
Mattress-based sleep trackers are nice if you don’t like wearing anything on your wrist or your fingers when you are asleep, but they do have several disadvantages. First, they can get fooled by your partner tossing and turning in bed, or if you roll off the area of the mattress where the sensor is.
Second, devices that sit on top of your mattress (including some smartphone apps that use your phone as the sleep tracker) can easily get knocked off onto the floor. Third, if you want to track heart rate, heart rate variability, or blood oxygenation levels, you need a wearable device anyways.
For most people, wearable sleep trackers provide better features than a mattress-based sleep tracker, but if you absolutely can’t stand wearing a device while you sleep, a mattress-based tracker might be a good fit.
Q: What is a sleep tracker ring?
A: Sleep tracker rings are like Fitbits for tracking sleep, except they sit on your finger instead of your wrist. Sleep tracker rings are newer innovations in sleep tracking technology that have been enabled by advances in sensor and battery technology.
If you hate having a big clunky device on your wrist when you sleep, a ring might be a better choice. They are super small and very easy to use.
The only downside to sleep tracking rings is that they don’t have the daytime functionality that many wrist-worn sleep trackers have—really all they do well is track sleep, and their battery capacity can’t measure up to wrist-worn devices.
Still, it’s a rapidly growing market, so expect to see big players step into the sleep tracking and fitness tracking ring arena soon.
Sleep trackers are devices that monitor when you go to sleep, when you wake up, and the quality of your sleep in between.
Basic devices will estimate your total sleep time and offer some metrics of tossing and turning, but the best devices can provide deeper insights, like your resting heart rate and heart rate variability while you’re asleep.
Further, you can even get data on your blood oxygen level from a device that has an SpO2 sensor, which can help identify sleep apnea events.
Tracking your sleep with a sleep tracker can be a great way to get objective data on your sleep, whether you are just trying to be a bit healthier by getting more rest or whether you are a serious athlete trying to optimize performance.
The objective nature of sleep trackers is a big help, because most people have very poor intuitions on the quality of their sleep, and many people who have sleep disorders like sleep apnea don’t even realize it. A sleep tracker helps hold you accountable, and can give you objective data about your sleep that you’d otherwise have no way to access.
For FitBug’s #1 sleep tracker recommendation, click here.