'ZDNET Recommends': What exactly does it mean?
ZDNET's recommendations are based on many hours of testing, research, and comparison shopping. We gather data from the best available sources, including vendor and retailer listings as well as other relevant and independent reviews sites. And we pore over customer reviews to find out what matters to real people who already own and use the products and services we’re assessing.
When you click through from our site to a retailer and buy a product or service, we may earn affiliate commissions. This helps support our work, but does not affect what we cover or how, and it does not affect the price you pay. Neither ZDNET nor the author are compensated for these independent reviews. Indeed, we follow strict guidelines that ensure our editorial content is never influenced by advertisers.
ZDNET's editorial team writes on behalf of you, our reader. Our goal is to deliver the most accurate information and the most knowledgeable advice possible in order to help you make smarter buying decisions on tech gear and a wide array of products and services. Our editors thoroughly review and fact-check every article to ensure that our content meets the highest standards. If we have made an error or published misleading information, we will correct or clarify the article. If you see inaccuracies in our content, please report the mistake via this form.
The best sleep trackers you can buy (and are they really accurate?)
Sleep is an elusive bedfellow. One-third of adults in the US don't get enough sleep, so it's no wonder there's an entire corner of the market for sleep products. When I realized how lack of sleep can cause daily stress, I took the leap and got a sleep tracker -- and it's been eye-opening.
Data explained why I felt tired when I checked my sleep score every day. Data showed me I wasn't getting enough sleep, plain and simple. Having the stats on my phone each morning motivated me to make better choices and improve my sleep hygiene.
Choosing the right sleep tracker for you can be a challenge. We explore the most popular options as well as some you may not have heard about to help you choose the best sleep tracker.
Also: How to sleep better with the Apple Watch
- Sleep cycle tracking
- All the features of a smartwatch
- No subscription to track sleep
- Must be paired with iPhone
- Shorter battery life than other wearables
Tech specs: Up to 18-hour battery life | Sleep cycles | Wi-Fi, Bluetooth, GPS, and/or cellular options | 41mm and 45mm models | IP6X dust and water resistant | Blood oxygen, body temperature sensor, EKG, irregular heart rate alerts | iOS only
Notoriously popular among both smartwatch and Apple fans, the newest Apple Watch comes with WatchOS 9 from the get-go. The Apple Watch now tracks how long you spend in bed and asleep, as well as sleep stages, like REM, core (light) sleep, and deep sleep.
The data is available as soon as you wake up, and, if you enjoy an Apple ecosystem, it can be paired seamlessly with your iPhone's focus mode to detect when you're awake.
According to ZDNET's own Christina Darby, "The Apple Watch became just as much of a nighttime accessory as my retainer. I loved having insight into the one thing I wasn't used to tracking -- my sleep."
Older compatible versions can also get sleep tracking through an iOS update, and the Apple Watch Ultra also tracks sleep, if you're wanting the most advanced rugged tech.
Read the review: Apple Watch 8 is a sleeper hit
- Long battery life
- Free six months Fitbit Premium with purchase
- Inexpensive
- Paid membership required to unlock all health features
- Limited functionality
Tech specs: Up to 10 days battery life | Sleep cycles | Bluetooth | 39.4 x 18.54 x 11.7mm | Up to 50m water resistant | Blood oxygen, skin temperature sensor, high/low heart rate alerts | iOS and Android compatible
One of the most popular wearable devices also used as a sleep tracker is the Fitbit. These fitness trackers use machine learning algorithms to convert data collected during the night into a sleep quality score, as well as sleep cycles.
Also: Apple Watch vs Fitbit for sleep tracking
With different styles at different prices, there is a Fitbit for everyone, from the most affordable and simple Inspire 3 to the advanced smartwatch Fitbit Sense 2.
A medical study on the accuracy of wearables to track sleep concluded that, while Fitbit models with sleep staging show a promising performance of tracking sleep cycles, though "they are of limited specificity" compared to advanced medical devices.
Read the review: Fitbit Inspire 3 review
- Not a wearable
- Consistent data
- Tracks snoring
- Not water-resistant
- Only tracks breathing and heart rate
Tech specs: Plug-in | Sleep cycles | Wi-Fi | 24 x 7 x 0.19 inches | Not water-resistant | Breathing and heart rate | iOS and Android
The Withings Sleep tracking pad is a slim device that goes under the mattress and tracks sleep cycles, breathing and heart rate, has snore detection, and puts the data together to give you an overall sleep score at the end of the night, much like the Fitbit.
These pads are popular among sleep tracking enthusiasts and can even help users detect sleep disorders like sleep apnea.
- Comprehensive sleep data
- Sleep and recovery scores
- Expensive
- No fitness tracking
Tech specs: 2.5 days battery life | Sleep cycles | 1.5 x 1.5 x 0.45 inches | Splash-proof | Blood oxygen, breathing and heart rate | iOS and Android compatible
The Biostrap EVO wearable health monitor collects data while you sleep to determine your sleep stages and overnight recovery levels. It provides users with comprehensive data that shows the quality of sleep they're getting.
Biostrap, the manufacturer of this sleep tracker, provides healthcare professionals and organizations with different devices for remote physiological monitoring of patients as well as for clinical research.
- Focused on sleep data
- Good battery life
- Sleek design
- No screen
- Paid membership required
- No step or calories tracking
Tech specs: Up to 5 days battery life | Sleep cycles | Bluetooth | 1.5 x 1.5 x 0.45 inches | IP68 water resistant | Blood oxygen, skin temperature sensor, heart rate | iOS and Android compatible
The Whoop 4.0 is a no-nonsense fitness tracker that doesn't have a screen. It's simply built to track fitness and sleep data, and it's an uncomplicated device.
Also: Whoop vs Apple Watch
As a fitness tracker, the Whoop 4.0 tracks strain, "defined as the measure of your cardiovascular load, scored on a scale of 0 to 21." This measure helps you see how your body performed during workouts and what kind of recovery you'll need.
Read the review: Screenless wearable helps you avoid injuries, track sleep details
- Nothing to wear
- Sunrise light
- Doubles as a smart alarm clock
- Requires specific placement for accuracy
- Paid membership to unlock all features
Tech specs: Plug-in | Sleep cycles | 5.2 x 6.7 x 1.45 inches | Wi-fi | Measures movement and breathing rate | iOS and Android compatible | Room temperature sensor, clock
The Halo Rise is a smart bedside sleep tracker that doubles as a wake-up light and smart alarm. This means that it gradually adjusts the built-in light to slowly wake you up, simulating the gradual brightening of the sunrise.
The smart alarm feature senses when you're in a light sleep stage to wake you up, much like some Fitbits do.
With no wearables involved, the Halo Rise sits on your bedside table, looking a lot like a makeup ring light, sensing your body movements and breathing rate to track when you fall asleep and your sleep stages. The jury is still out on non-contact bio-motion sensing devices, but some studies have found they can be relatively accurate. The most common error is failing to detect when you wake up.
- Comfortable enough to sleep in
- Guided and unguided meditation
- Paid subscription to unlock all benefits
- Can be uncomfortable in some positions
Tech specs: Up to 10-hour battery life | Heart, mind, breath and body meditation (soothing guidance and soundscapes) | Sleep tracking with deep sleep intensity points, heart rate, and sleep score | Comfort fit headband | Pair with the free Muse app |
The Muse S meditation headband not only tracks your sleep but also helps you fall asleep through guided and unguided meditation. You can start the night with relaxing meditation, and the device will notice when you drift away, making it a dual-purpose wearable.
Meditation is a practice that can add many health benefits to your life, like lowered blood pressure and less stress and anxiety, according to different studies.
Muse S can sense when you wake up in the middle of the night and can automatically play more audio to lull you back to sleep.
Read the review: I slept with a meditation headband, Here's why you should, too
- Sleek, easy to blend in with regular jewelry
- Long battery life
- Paid membership required to unlock all features
Tech specs: Up to 7 days battery life | Sleep cycles | Bluetooth | 7.9mm wide, 2.55mm thick | Up to 100m water resistant | Blood oxygen, skin temperature sensor, heart rate monitoring | iOS and Android compatible
Another wearable device is the Oura Ring which, unlike other more popular trackers, is worn on a finger rather than wrist. Oura claims to accurately track sleep cycles, total sleep time, resting heart rate, heart rate variability, and movement. The technology combines and converts this information into a sleep score.
Compared to a polysomnography, a medical test used to diagnose sleep disorders, the Oura ring proves to be 96% accurate in detecting sleep. More specifically, the Oura ring is 65% accurate in detecting light sleep, 51% for deep sleep, and 61% for REM sleep.
According to ZDNET's Matthew Miller, a new sleep tracking algorithm "will provide even more accuracy that we already see with the Oura Ring" in future updates.
Read the review: Oura Ring 3 review: Unobtrusive 24/7 health tracking with more to come in 2022
What is the best sleep tracker?
The best sleep tracker overall is the Apple Watch Series 8. Data has the power to reveal our habits and motivate us to improve. We may be unaware of habits that have a negative effect on our health, so being able to trust the accuracy of the data is key.
Apple Watch's sleep tracking abilities make it stand out from the rest. It combines the data it gathers each night to best approximate your sleep quality and cycles. The bonus? Apple's smartwatch comes with many other features, too.
A simpler option like a Fitbit, for example, may be more suitable for those not interested in all the bells and whistles of the Apple Watch.
| Sleep tracker | ZDNET's take | Price | Battery life | Sleep cycles | iOS & Android | Subscription offered? |
| Apple Watch Series 8 | Best overall | $359 | 18 hours | ✔ | iOS only | No |
| Fitbit Inspire 3 | Best for a budget | $79 | 10 days | ✔ | ✔ | Yes |
| Withings Sleep Pad | Best under-mattress tracker | $130 | Plugged in | ✔ | ✔ | No |
| Biostrap EVO | Best for data fans | $319 | 2.5 days | ✔ | ✔ | No |
| Whoop 4.0 | Best alternative to Fitbit and Apple | $300 | 5 days | ✔ | ✔ | Yes |
| Halo Rise | Best bedside option | $140 | Plugged in | ✔ | ✔ | Yes |
| Muse S | Best headband tracker | $350 | 10 hours | ✔ | ✔ | Yes |
| Oura Ring | Best for 24/7 monitoring | $299 | 7 days | ✔ | ✔ | Yes |
Which is the right sleep tracker for you?
This will vary from person to person according to individual preferences. I first used a sleep tracker when my kids were babies, and you can thank the obsessive in my OCD for buying a couple different trackers.
Those devices only measured time asleep, heart rate, and blood oxygen levels, but nowadays I enjoy sleeping in my Fitbit Inspire 2 and Apple Watch to see data each morning.
After switching from Fossil to Apple to Fitbit, I really enjoy the simplicity of the Fitbit Inspire 2, but, most of all, I enjoy the sleep stages breakdown. Maybe it's that OCD again, but give me some data to obsess over and I'll buy into whatever you're selling.
With a Fitbit and other devices like the Withings mat, you get a snapshot of what your sleep cycles looked like in nights past: How long you were asleep, in which sleep stages, and how long did each cycle last.
After that, it's all a matter of preference: wristband, headband, mattress pad, etc.
| Choose this sleep tracker... | If you want... |
| Apple Watch Series 8 | An accurate sleep tracker that fits seamlessly into your Apple ecosystem |
| Fitbit Inspire 3 | Long battery life with effective sleep tracking algorithms |
| Withings Sleep Pad | An under-the-mattress solution that doesn't interfere with your sleep |
| Biostrap EVO | Compehensive data results in your phone or tablet each morning |
| Whoop 4.0 | No frills, just sleep and fitness data with no screens or notifications |
| Halo Rise | A no-contact bedside tracker with bonus wakeup light and smart alarm |
| Muse S | A sleep headband complete with meditation |
| Oura Ring | A 24/7 device that you won't even remember you're wearing |
How did we choose these sleep trackers?
Poor sleep quality can lead to an increased risk of dementia, obesity, cardiovascular disease, depression, and even certain types of cancer. Motivation to avoid these ailments is motivating enough to get me to track my sleep in hopes of identifying and improving my bedtime habits.
The craving for health information is constant nowadays. We want to track calories and macros in our diet, along with heart rate, and even blood oxygen level. Quality sleep has become another lifestyle habit to track.
With health and tech companies creating new sleep devices, aids, and trackers, it's no wonder the market is flooded.
To find the best sleep trackers, I used my personal experience and thorough research into product quality as well as sleep studies on these devices.
What is a sleep cycle?
A sleep cycle is comprised of three different stages: light sleep, deep sleep, and rapid eye movement, or REM. On a typical night, when you first fall asleep, you'll enter either light or deep sleep, likely one after the other, and enter a REM phase.
This cycle will last about 1.5 hours, then repeat itself in intervals closer to two hours, maybe with a few awake minutes in between, but always ending with REM sleep. As the night progresses, you'll likely experience less time in deep sleep, while the REM stages will become longer.
A regular night of sleep should be about 50% light sleep, 20% REM sleep, 20% deep sleep, and 10% awake.
Also: A hidden feature on your iPhone may help you sleep better
Are sleep trackers really accurate?
If you need your sleep analyzed, doctors will usually order a polysomnography, which analyzes a person's oxygen level, heart rate, breathing, eye movement, and leg movement while simultaneously running an electroencephalogram (EEG).
An EEG shows your brainwaves through different stages and cycles of sleep. A wearable smartwatch or fitness tracker on your wrist, however, is far from your brain.
The most popular wearables by Fitbit, Apple, Garmin, and Samsung collect a combination of the following measurements: heart rate and heart rate variability (HRV), movement, breaths per minute, and skin temperature. Devices that track sleep cycles use an algorithm to hypothesize your sleep cycles based on the data.
A 2017 study compared a polysomnography with the performance of a Fitbit Charge 2 in 35 adults. Researchers found the Fitbit device detected sleep onset with 96% accuracy but overshot time spent asleep by 9 minutes on average. In the study, the Fitbit detected light sleep with 81% accuracy, deep sleep with only 49% accuracy, and REM sleep with 74% accuracy.
A newer study published in April of 2022 compared the performance of Fitbit Alta HR to results of an EEG conducted simultaneously on 40 college athletes while sleeping. This study found FItBit data to satisfactorily track sleep onset, time spent asleep, and sleep cycles. Fitbit can be a useful tool for athletes' sleep management.
While not 100% accurate, the Fitbit data had a strong correlation with polysomnography data.
Which sleep trackers are more accurate: wearables or no-contact?
Wearable sleep tracking devices combine data collected by several sensors to track sleep cycles. The devices typically track heart rate, movement, breathing rate, skin temperature, and previous data, like your resting heart rate.
No-contact sleep trackers, however, like the Halo Rise, rely on sensing movement, so it monitors your breathing and body movements, as well as environmental factors like light, temperature, and noise levels.
Though companies tout their own tracker as the most accurate, we can't say for sure unless all devices are compared with polysomnography, which is the gold standard for sleep tracking.
Are there alternative sleep trackers worth considering?
With so many sleep trackers available, there are many alternatives worth considering. Here are our top picks for alternative sleep trackers: