Sleep Apps · Review
Sleep Cycle Review
The veteran sleep tracker and smart alarm that wakes you in your lightest sleep phase.
Our rating
4.3 / 5
Starting price
Free, then ~$39.99/yr
Free tier
Yes
Platforms
iOS · Android
Developer
Sleep Cycle AB
Launched
2009
Our verdict
Sleep Cycle is the most established phone-based sleep tracker, and its smart alarm — waking you during light sleep within a window — is genuinely pleasant. It is a measurement and waking tool, not a relaxation or therapy app. Treat its data as directional, not clinical, and it earns its place.
This review is editorial and unsponsored — no affiliate payments influence our ratings. Selfpause makes a wellness app of its own, so where a product competes with us, we say so plainly and let you judge.
Sleep Cycle has been tracking sleep from a phone on the nightstand since 2009, long before wearables made it common. It uses the microphone (and optionally the accelerometer) to estimate your sleep phases and wakes you with a smart alarm during your lightest sleep.
That smart alarm is the reason most people stay. Being eased awake during light sleep, rather than jolted out of deep sleep, makes a real difference to how groggy you feel — and you do not need to wear anything to get it.
It also logs trends, detects snoring, and records sleep sounds. Just keep expectations calibrated: phone-based tracking is an estimate, not a medical-grade measurement, and the app is about measuring and waking, not relaxing you to sleep.
Pros & cons
What we like
- Smart alarm wakes you in light sleep within a chosen window — noticeably gentler mornings.
- No wearable required — it works from the nightstand.
- Long track record and a mature, reliable app.
- Useful trends, snore detection, and sleep-sound recordings.
- Reasonable annual price.
What we don’t
- Phone-based tracking is an estimate — less accurate than a good wearable.
- It measures sleep; it does not actively help you fall asleep.
- Best features (trends, online backup) require Premium.
- Microphone-based tracking raises understandable privacy considerations.
Best for / avoid if
Best for
- →People who want gentler wake-ups without buying a wearable
- →Anyone curious about their sleep trends over time
- →Light sleepers who hate being jolted awake
- →Those who snore and want to monitor it
Avoid if
- →You want clinical-grade accuracy — see a sleep study or a dedicated wearable
- →You want help falling asleep — a soundscape or CBT-I app fits better
- →You are uncomfortable with microphone-based tracking overnight
Pricing
Free
$0
Basic tracking and the smart alarm.
Premium
~$39.99/yr
Detailed trends, snore detection, online backup, and more.
What Sleep Cycle is
Sleep Cycle is a sleep-tracking app and smart alarm. It estimates your sleep phases overnight using your phone and wakes you during light sleep within a window you set.
It is a measurement-and-waking tool. It tells you about your sleep and improves your wake-up; it is not designed to relax you into sleep the way a soundscape or meditation app is.
Why the smart alarm matters
Waking during deep sleep is what produces that drugged, groggy feeling. Sleep Cycle watches for a light-sleep moment inside your alarm window and wakes you then, so mornings feel less brutal.
It is a small idea with an outsized daily payoff — and because it needs no wearable, the barrier to trying it is just installing an app.
Smart alarm
You set a wake-up window; the app finds your lightest sleep within it and wakes you then.
This is the standout feature and the main reason long-term users keep it on the nightstand.
Trends and snore detection
Premium logs long-term sleep trends and can detect and record snoring through the night.
The trends are useful for spotting patterns; just remember the underlying data is an estimate, not a clinical reading.
Where Sleep Cycle falls behind
Accuracy. A dedicated wearable or a clinical sleep study measures sleep far more precisely.
Helping you sleep. It does not relax you; pair it with a soundscape or CBT-I app if falling asleep is the problem.
Privacy comfort. Overnight microphone use is reasonable to be cautious about.
Sleep Cycle vs. BetterSleep vs. Calm
These solve different halves of the sleep problem. Sleep Cycle measures sleep and wakes you gently. BetterSleep and Calm help you fall asleep with soundscapes and stories.
If your issue is groggy mornings or curiosity about your patterns, Sleep Cycle is the pick. If your issue is lying awake unable to drift off, a relaxation app like BetterSleep or Calm is what you actually need.
Plenty of people run both: one to get to sleep, one to wake up well.
Bottom line
Sleep Cycle is the best no-wearable way to wake up gently and watch your sleep trends. If your real problem is falling asleep, pair it with — or choose instead — a relaxation app like BetterSleep or Calm.
Want a daily positivity practice in your own voice? Selfpause lets you record personalized affirmations, layer them with calming music, and keep them on your lock screen.
Try Selfpause FreeAlternatives to Sleep Cycle
BetterSleep
4.3Soundscape-first app to help you actually fall asleep.
Read our review →
Calm
4.5Sleep Stories and relaxation for getting to sleep.
Read our review →
Headspace
4.5Sleepcasts plus a full meditation curriculum.
Read our review →
Frequently asked questions
Is Sleep Cycle accurate?+
It is a reasonable estimate for a phone-based tracker, useful for spotting trends — but it is not as accurate as a quality wearable or a clinical sleep study.
Does Sleep Cycle help you fall asleep?+
Not really. It tracks sleep and wakes you gently. To fall asleep faster, use a soundscape or relaxation app like BetterSleep or Calm.
Does it work without a smartwatch?+
Yes — that is the point. It tracks from your phone on the nightstand, no wearable required.
Is the free version enough?+
The free version covers basic tracking and the smart alarm. Trends, snore detection, and backup require Premium.
A note on mental health: apps and online services can support wellbeing, but they are not a substitute for professional care. If you are struggling, a licensed professional can help — and if you are in crisis, contact your local emergency number or, in the US, call or text 988 (Suicide & Crisis Lifeline).
More sleep apps reviews
Sleepio
4.6Not a relaxation app — a clinically validated CBT-for-insomnia program in digital form.
BetterSleep
4.3The soundscape-first sleep app, formerly Relax Melodies, with a generous free tier.
Endel
4.2The adaptive soundscape engine — AI-generated audio that reshapes itself to your time, weather, and heart rate.