Apple Watch · Apps

Track sleep stages and wind down with the Sleep app

The Sleep app on Apple Watch tracks time asleep and, on supported models, sleep stages (REM, Core, Deep, Awake) using motion and heart rate data, working alongside Sleep Focus and wind-down schedules set in the Health app.

What you should know

  • Sleep schedules, including bedtime and wake time, are configured in the Health app on iPhone under Browse → Sleep → Full Schedule & Options.
  • Sleep stage tracking (REM, Core, Deep) requires an Apple Watch Series 6 or later; earlier models only track total sleep time.
  • Wind Down mode dims the iPhone screen and can silence notifications ahead of bedtime.

Why it matters

Sleep tracking only works if the watch has enough charge to survive the night, which is why it's usually paired with a short charging routine earlier in the day — understanding that trade-off prevents missed sleep data.

Best practices

  • Charge the watch for 30-60 minutes in the evening before bed if your daytime charge is already low.
  • Turn on Sleep Focus so calls and notifications don't disturb sleep while tracking stays active.

Common problems and fixes

No sleep data recorded overnight
Check the watch had enough charge and was actually worn — sleep tracking requires the watch on your wrist through the night.
Sleep stages not showing, only total time
Confirm your watch model is Series 6 or later, or Ultra/Ultra 2 — older models can't detect sleep stages.

Tips and tricks

  • Enable the Sleep complication on your watch face to see last night's sleep duration at a glance.

Frequently asked questions

Do I need to manually start Sleep Tracking?

No — once a sleep schedule is set up in the Health app, tracking happens automatically during your scheduled sleep window.

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