Start a fast
Pick a length from 16:8 to three days. One button starts it, and you can move the start time if you forgot.
13:2483% of 16h goal
Free on the App Store
The fasting app that actually keeps you going.
A timer, an hour-by-hour guide, and a check-in that answers back when a fast gets hard. No account. Your fasting data stays on your phone.
- Free to start
- No account or sign-up
- iPhone and Apple Watch
How it works
Three things, done well.
Most fasts don't end because of the plan. They end in one hard half hour. StayFasted is built around that half hour.
Check in when it gets hard
Say how you feel. The reply answers what you wrote, and it never pushes you to carry on.
😞Low
😤Tough
😌Okay
💪Strong
Hunger tends to come in waves, and a wave often passes in 15 to 20 minutes. If it doesn't, ending the fast is a fine choice too.
End it well
Stop whenever you choose. A refeed guide walks you back to food gently, and your history shows what you did.
NowStart with liquids
+2hLight, easy foods
+6hSoft whole foods
+12hNormal eating
Inside the app
Everything a fast needs. Nothing it doesn't.
Four screens do most of the work.
The guide
Know what to expect, hour by hour.
For each part of a fast: what is generally understood, what people often feel, and what tends to help. Timing differs from person to person.
Fed state
Your body is digesting your last meal.
Early fasting
Digestion is finishing. The first mild hunger often arrives at your usual mealtimes.
Stored energy
Your body is drawing on stored glycogen. Hunger tends to come in waves, and pass.
Shifting to fat
Many people start using more fat for fuel around now. Some notice clearer focus, others a dip.
Running on fat
Fat is likely your main fuel by now. Keep drinking water, and keep warm.
Day two
A longer fast. Electrolytes start to matter more.
Extended fast
Go gently, keep up water and electrolytes, and eat if you feel unwell.
Long fast
Plan a gentle first meal, and check with your doctor before fasting this long.
General information, not medical advice. If you are pregnant, under 18, have diabetes or an eating disorder, or take medication, talk to your doctor before fasting.
Breathe
For the hard minutes of a fast.
Short breathing sessions for when a craving arrives, and a guided deep rest for when you need to lie down for ten minutes. Two sessions are free, and they run on Apple Watch too.
- Hunger wave · 2 min
- Quick reset · 1 min
- Deep rest · 10 min
Privacy
Your fasting data stays on your phone.
No account
No email, no login, no sign-up wall. Download the app and start.
Stored on your iPhone
Your fasts, check-ins, photos and notes are saved on your device. There is no StayFasted server holding them.
AI that runs on your phone
Replies to your check-ins are produced on your iPhone. What you write is not sent to a server.
Three things that use the internet, if you turn them on
Weather sends an approximate location to Apple Weather. Scanning a drink looks its barcode up at Open Food Facts. Apple Music playlists come from Apple. All three are optional.
Pricing
Start free. Upgrade if it helps.
The free app is a complete fasting timer. Pro adds the AI replies, the full history and the deeper tools.
Free
$0
Everything you need to start and finish a fast.
- Timer for every fasting length
- The hour-by-hour guide
- Check-ins and fluid tracking
- Refeed guide
- Two breathing sessions
- Your last 10 fasts and 7 days of charts
Pro Yearly or monthly
$39.99 a year
About $3.33 a month. Or $5.99 billed monthly. Cancel any time.
- Everything in Free
- AI replies on every check-in
- All breathing sessions and deep rest
- Full analytics and a monthly report
- Unlimited history, journal, measurements and supplements
- Rhythm planner, drink scanner, photo comparison, Health Labs and export
Lifetime
$49.99 once
Everything in Pro, with one payment and no renewals.
- Everything in Pro
- Pay once, keep it
- Future Pro features included
Prices in US dollars and may differ by country. Purchases are made in the app through the App Store. Subscriptions renew until cancelled in Settings.
Is StayFasted really free?
Yes. The timer, the hour-by-hour guide, check-ins, fluid tracking and the refeed guide are free, with no time limit. Pro is there if you want the AI replies, full history and the deeper tools.
Do I need to make an account?
No. There is no account and nothing to sign up for. Your fasting data is stored on your iPhone.
Is fasting right for me?
That is a question for your doctor, not an app. Fasting is not suitable for everyone, including people who are pregnant or nursing, under 18, living with diabetes or an eating disorder, or taking certain medication. StayFasted gives general information and is not medical advice.
What if I want to stop a fast early?
Then stop. Ending a fast is always a fine choice, and the app will never tell you otherwise. The hours you did are saved either way.
What does the AI do?
When you check in, it replies to what you wrote, how you feel and why you started. It runs on your iPhone, so what you write is not sent to a server. On iPhones without Apple Intelligence, replies are chosen from a written library instead. AI replies are part of Pro.
Does it work with Apple Health and Apple Watch?
Yes, both are optional. With your permission the app reads weight, steps, sleep, resting heart rate and active energy from Apple Health, and saves weight, water and mindful minutes. The Watch app shows your fast, logs water and runs breathing sessions.
How do I cancel Pro?
In the Settings app on your iPhone: tap your name, then Subscriptions. If you cancel, you keep what you recorded while you were subscribed.
Start your next fast with company.
Free on the App Store. No account, no sign-up.
Download for iPhone