Sleep is the foundation of our daily well-being and long-term health. That’s why we’ve developed a new, smart, and personalized approach to sleep evaluation — to help you improve your sleep if needed, ease anxiety when everything is fine, and understand how sleep affects your overall wellness.
Please note that the new Sleep Analysis is currently available only to iOS users with Apple Watch. It is being gradually rolled out, so it may become available later. The previous version of the Sleep Analysis will remain available for users who don’t yet have access to the new Sleep Analysis on the Today screen.
If you have any feedback or requests for new features about sleep, please share them with us through the Report a problem form. Also, you can use a feedback form in the Sleep Report. For that:
Open the Sleep Report
Scroll to the screen Dreaming of a better report?
Click the Share my thoughts button
Fill out the report
Click the Submit button
How We Analyze Sleep
Our complete sleep analysis is based on raw data your Apple Watch tracks. Simply wear your Watch while you sleep to receive the detailed insights.
If you didn’t wear your Watch while sleeping, but still see the Sleep Widget on the Today screen, you can add your sleep time manually. This helps us provide you with a more consistent analysis and offer better recommendations for your ideal bedtime, wake up time, and overall sleep needs.
Sleep Data
To make it as convenient as possible for you to view all the key data your Apple Watch tracks overnight, we’ve compiled everything into a multifunctional chart. This chart displays your heart rate, activity, noise levels, respiration rate, SpO2, and sleep stages.
We hope this data helps you assess how accurately we’ve identified your sleep/wake times and periods of wakefulness. If something doesn’t seem right, you can adjust the sleep boundaries by tapping Edit data in the pop-up window or using the pencil icon in the top right corner.
Sleep Insights
This section provides an overview of your sleep patterns and various aspects from the past week, and a closer look at last night’s sleep. Remember, everyone has good and bad nights, but the key is to focus on the bigger picture: how consistently you wake up in the morning, whether you’re getting enough sleep overall, how often you’re waking during the night, and whether you’re recovering well.
Sleep Score
The Sleep Score provides an overall evaluation of your sleep quality. It is a comprehensive assessment based on four key parameters: sleep balance, sleep schedule, sleep stability, and heart rate wave.
Sleep Balance
The Sleep Balance refers to the ratio between the time you slept (total time in bed, minus awake periods) and your sleep need (how much sleep your body requires to feel rested). Both oversleeping and insufficient sleep can be harmful, so maintaining a healthy balance is essential.
Sleep Schedule
This parameter evaluates how consistent your sleep routine is.
Ideally, you should go to bed and wake up around the same time every day. However, if you’re particularly tired and need more sleep, it’s best to go to bed earlier, but still wake up at your usual time.
A consistent Sleep Schedule helps your body regulate melatonin production, making it easier to fall asleep, stay asleep, and wake up refreshed. Consistency also promotes deeper, more restorative sleep by allowing your body to enter the sleep stages crucial for recovery, ultimately improving your overall health.
Sleep Stability
This parameter evaluates how restless your sleep was and if the frequency and duration of your wake periods are concerning.
It’s important to remember that waking up several times during the night is normal and a natural part of transitioning between sleep cycles. Typically, there’s no need to worry unless you experience multiple moderate (5–12 minutes) or extended wake-ups (more than 12 minutes).
Heart Rate Wave
The Heart Rate Wave is an experimental metric that reflects how restorative your sleep was based on your heart rate patterns.
The graph in this section has three key components:
Your baseline. To accurately calculate your baseline, we need at least 30 nights of sleep data with your Apple Watch on. The baseline is based on your best recovery nights. If you generally have poor sleep, the baseline may not be ideal, but it still helps you see whether a given night’s heart rate wave is better or worse than usual. The baseline will adjust over time as your recovery patterns change.
Colored dots. These dots represent heart rate values recorded by your watch throughout the night.
Smoothed pulse wave. This wave is created by smoothing out the heart rate values. Its color depends on how those values compare to your baseline.
We evaluate your heart rate wave based on several factors:
Wave elevation relative to your baseline. This shows if your heart rate was higher than usual. A higher heart rate during sleep can indicate lower sleep quality, with less time spent in deep, restorative stages.
Wave shape. Ideally, the wave should resemble a hammock — your heart rate decreases until melatonin levels peak in the middle of the night, then increases as cortisol rises toward wakefulness. If the wave deviates from this shape, it may suggest that your sleep was not fully restorative.
Heart rate before waking. This shows how ready your body was to wake up. If your heart rate is lower than your baseline, it might indicate that your body wasn’t ready to wake up. If it’s higher, it could suggest insufficient recovery during the night.
Sleep Impact
This section helps you understand how your sleep from the previous night will affect your day. It provides insights into how much energy you’ll have, whether you’ve recovered from stress, and how well you’ll be able to handle the challenges of the new day.
Nighttime Recharge
This section shows how your body recharges during different sleep stages. Your «battery» recharges more effectively when you get sufficient deep and REM (rapid eye movement) sleep each night.
Deep sleep repairs your body by restoring bones, muscles, and tissues.
REM sleep helps process emotions and maintains brain health.
Your brain naturally determines how much deep and REM sleep you need each night. To support this process, ensure you get enough total sleep and try these tips:
For more deep sleep, stick to your sleep schedule and go to bed within your optimal sleep window.
For more REM sleep, avoid alcohol before bed and try to minimize or eliminate the use of sleep aids if possible.
If these strategies don’t help, it’s recommended to consult your doctor.
Morning Pressure
Your sleep determines how easily you will handle the challenges of the new day.
If you haven’t had sufficient sleep, it can create pressure in your body’s regulatory systems, forcing your body to use more energy to function and reducing your resilience to daily stressors.
However, if you’ve slept well, it helps release the pressure from the previous day and recharge your stress resilience for the day ahead.
Sleep Need Forecast
This feature shows how your need for sleep builds up throughout the day. It’s influenced by how well you slept the previous night, your usual sleep patterns, and your daily activity, stress levels, and rest. On highly active or stressful days, your need for sleep will increase compared to your usual levels. On more relaxed days, it may decrease.
Sleep Guidance
This section appears in the evening, once we’ve calculated your optimal bedtime and wake up time.
Sleep and Rise Windows
The recommendations for your Sleep and Rise Windows vary from day to day based on your daily routine and accumulated sleep need, while still considering your usual schedule. If your schedule is inconsistent, your Sleep and Rise Windows will be wider to account for the variability.
However, maintaining a consistent sleep and wake time helps your body regulate melatonin (for sleep) and cortisol (for waking) more effectively. This makes it easier for you to fall asleep, stay asleep throughout the night, and wake up refreshed in the morning.
FAQ
Some data are not displayed in the sleep data chart. What should I do?
1. Heart rate is not displayed
If you slept with your watch on, but your heart rate wasn’t recorded, your watch may have been in power-saving mode, which either disables heart rate tracking or records it infrequently.
If your heart rate data is available in Apple Health but not displayed in Welltory, please send us a bug report by going to Menu → Report a problem, describe the issue, and we’ll investigate what went wrong.
2. Tossing & turning is not displayed
This indicator is calculated based on Active Energy data from Apple Health. Please ensure that you’ve granted Welltory access to this data by going to Apple Health → Profile → Apps and Services → Welltory → and enabling Allow Welltory to read.
If this data isn’t recorded for several days in a row despite permissions being granted, please send us a bug report through Menu → Report a problem, describe the issue, and we’ll investigate what went wrong.
3. Noise (Environmental Sound Levels) is not displayed
This feature is available for Series 4 Apple Watch and above, running iOS 13 and watchOS 6+.
First, ensure that noise data is being recorded. Open the Watch app on your phone, scroll to Noise, and turn it on.
If it’s already enabled, confirm that Welltory has permission to access Environmental Sound Levels by going to Apple Health → Profile → Apps and Services → Welltory → and enabling Allow Welltory to read.
If this data isn’t recorded for several days despite permissions being granted, please send us a bug report through Menu → Report a problem, describe the issue, and we’ll investigate what went wrong.
4. Respiratory Rate is not displayed
This feature is available for Series 3 Apple Watch and above, with iOS 15+ and watchOS 8+.
To ensure Respiratory Rate is recorded, make sure the Track Sleep with Watch setting is enabled. Open the Watch app on your phone, scroll to Sleep, and enable Track Sleep with Watch.
Additionally, check the Privacy section in the Watch app to confirm that this stream is enabled.
If it’s already on, ensure that Welltory has permission to access Respiratory Rate by going to Apple Health → Profile → Apps and Services → Welltory → and enabling Allow Welltory to read.
Lastly, Respiratory Rate will only be recorded if Sleep Mode is enabled on your watch. This mode turns on automatically if you have a sleep schedule set up on your phone. If not, you can enable it manually by tapping the bed icon on your watch.
5. SPO2 (Blood Oxygen) is not displayed
This feature is available for Series 6 Apple Watch and above.
To ensure Blood Oxygen data is recorded, make sure the Track Sleep with Watch setting is enabled. Open the Watch app on your phone, scroll to Sleep, and enable Track Sleep with Watch.
Additionally, check the following settings in the Watch app:
In the Privacy section, confirm that the Blood Oxygen stream is enabled.
In the Blood Oxygen section, ensure all toggles are turned on.
6. Sleep stages are not displayed
To display sleep stages, you need to wear your watch while sleeping.
Additionally, ensure that Welltory has access to both Heart Rate and Active Energy data in Apple Health by going to Apple Health → Profile → Apps and Services → Welltory → and enabling Allow Welltory to read for these data streams.
Why do sleep stages in Welltory differ from Apple Health or other sleep trackers?
We calculate the duration and timing of each sleep stage using our proprietary algorithms, which may result in differences compared to the sleep stages displayed in Apple Health or other sleep trackers.
Why do my sleep duration and time calculations update after I wake up and view my analysis?
Sometimes the Apple Watch requires additional time to sync with Apple Health, which is where we access the data used in our analysis. As a result, we rely on the data that has been synced and update your analysis once we receive more refined data from Apple Health.
Why add sleep and wake times if I didn't sleep with my watch on?
Sleep and wake up times, along with total sleep duration, are key indicators for evaluating your sleep routine and providing the most accurate Sleep Guidance. The more accurately we understand your sleep patterns, the better our recommendations and analysis will be for the nights when you do sleep with your watch on.
Also, knowing your sleep time allows us to calculate your energy levels, which are displayed in the Battery section.
Why don't I receive sleep messages in my feed anymore?
If you’re receiving the new sleep analysis on the Today screen, you will no longer receive sleep messages in your feed. We’re moving the most important sleep information to a more accessible place.
Additionally, we’re currently working on developing the Journal, where soon a sleep message based on the new analysis will be saved.
How can I view sleep data for previous days?
You can view the previous day’s scores and main parameters in the Sleep Report under the Days tab. While the raw data graph and pulse wave are not yet available for the previous days, we’ll add this feature soon.
How do I correct sleep time?
To adjust the start or end time of your sleep, use the Edit button in the pop-up window within the sleep analysis, or click on the pencil icon in the top right corner of the sleep analysis screen.
Please note that, for now, you can only correct the sleep data from the current day.
Why don't I see the new sleep analysis?
The new sleep analysis is currently only available to iOS users with an Apple Watch. If you meet these criteria, the new sleep analysis will be available to you soon, as we’re rolling it out gradually.