Sleep is the foundation of everything — your mood, focus, and health throughout the day. Yet most people have no idea how well they actually sleep. A sleep tracker helps you spot patterns, find problems, and make small changes that lead to better rest. Here are the best free options for iOS and Android.
Sleep Cycle
Sleep Cycle uses your phone's microphone and accelerometer to detect sleep phases and wake you during the lightest part of your cycle. The result is you wake feeling refreshed rather than groggy, even if the alarm fires a few minutes earlier or later than scheduled.
- Smart alarm wakes you in a 30-minute window at the lightest sleep phase.
- Motion and sound analysis tracks sleep without any extra hardware.
- Long-term sleep trend graphs show how stress, activity, and habits affect your rest.
- Sleep notes let you log caffeine, exercise, and mood to find patterns.
- Integrates with Apple Health, Google Fit, and Samsung Health.
Sleep as Android
Sleep as Android is the most feature-packed free sleep tracker on Android. It uses motion sensing to map your sleep cycles, captures snoring audio, and includes a smart alarm that works even with Wear OS and Garmin watches.
- Smart alarm with gradual wake-up sounds that sync with your sleep stage.
- Snore and noise recording with automatic night replay.
- Works with Wear OS, Garmin, Mi Band, and other fitness wearables.
- Lucid dreaming cues and sleep talk detection built in.
- Detailed charts showing REM, deep, light, and awake time per night.
Pillow
Pillow is the go-to sleep tracker for iPhone and Apple Watch users. It automatically detects when you fall asleep, records your overnight audio, and breaks down sleep stages into a clear timeline with heart rate data layered in.
- Automatic sleep detection requires no setup — just charge your watch and sleep.
- Heart rate and blood oxygen overlaid on the sleep stage timeline.
- Audio recordings capture snoring, talking, and coughing during the night.
- Sleep quality score with actionable tips each morning.
- Weekly and monthly trends with intuitive charts.
ShutEye
ShutEye combines sleep tracking with a rich library of sleep sounds, white noise, and ASMR content. The free tier gives you snore detection, basic sleep stages, and access to hundreds of ambient sounds to help you fall asleep faster.
- Snore detection with intensity graph across the night.
- 200+ sleep sounds including white noise, rain, nature, and ASMR.
- Smart alarm with gradual sunrise lighting effect.
- Sleep diary to log how you feel and what you consumed that day.
- Weekly reports showing sleep duration and quality trends.
Rise Sleep
Rise Sleep focuses on your sleep debt and predicts your energy levels throughout the day. Instead of tracking sleep stages, it shows you when your focus peaks, when you'll feel a slump, and how to plan your day around your biology.
- Sleep debt meter shows cumulative hours you owe your body.
- Energy schedule predicts focus peaks, afternoon slump, and wind-down time.
- Daily sleep and wake time recommendations to pay off sleep debt.
- Habit nudges for consistent bedtime, caffeine cutoffs, and screen limits.
- Science-based explanations for each recommendation.
BetterSleep
BetterSleep is built around one idea: falling asleep faster through sound. It offers a huge free library of sleep sounds, stories, and binaural beats, combined with basic sleep tracking so you can see whether the sounds actually help.
- Sound mixer lets you layer up to 5 tracks — rain, fire, ocean, pink noise, and more.
- Sleep stories narrated by soothing voices to distract an overactive mind.
- Guided breathing and body scan exercises for pre-sleep relaxation.
- Basic sleep stage tracking using phone motion sensors.
- Sleep diary to correlate which sounds improved your rest.
Samsung Health
Samsung Health comes pre-installed on Galaxy devices and tracks sleep automatically without any setup. If you own a Galaxy Watch, it adds heart rate, blood oxygen, and snore detection on top of the motion-based phone data.
- Fully automatic sleep detection — no timers or manual tracking needed.
- Galaxy Watch adds heart rate, SpO2, and snore detection data.
- Sleep score summarizes duration, efficiency, and cycles in one number.
- Integrates sleep data with steps, stress levels, and heart rate history.
- Weekly summaries with plain-language tips to improve your next week.
Headspace
Headspace is primarily a meditation app, but its sleep section is one of the most polished available. Sleepcasts — narrated audio journeys — are the standout feature: they give your mind something calm to focus on while your body falls asleep.
- Sleepcasts guide your imagination through calming scenes until you drift off.
- Wind Down routines with music, breathing, and movement before bed.
- Morning meditations to start the day with the right mindset.
- Sleep sounds mixer for ambient background during the night.
- Anxiety-reduction exercises designed for racing thoughts at bedtime.
Calm
Calm's sleep offering centers on Sleep Stories — bedtime tales narrated by calming voices specifically designed to slow your thoughts. Add hundreds of nature sounds and guided breathing, and you have a solid wind-down toolkit.
- Sleep Stories: bedtime narratives that calm your mind naturally.
- Hundreds of nature sounds and ambient sleep music tracks.
- Daily Calm: a 10-minute guided session you can use morning or night.
- Breathing exercises including box breathing and the 4-7-8 technique.
- Sleep and mood journal to spot patterns over time.
