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.
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.
How it works
Most fasts don't end because of the plan. They end in one hard half hour. StayFasted is built around that half hour.
Pick a length from 16:8 to three days. One button starts it, and you can move the start time if you forgot.
Say how you feel. The reply answers what you wrote, and it never pushes you to carry on.
Stop whenever you choose. A refeed guide walks you back to food gently, and your history shows what you did.
Inside the app
Four screens do most of the work.
The guide
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.
Your body is digesting your last meal.
Digestion is finishing. The first mild hunger often arrives at your usual mealtimes.
Your body is drawing on stored glycogen. Hunger tends to come in waves, and pass.
Many people start using more fat for fuel around now. Some notice clearer focus, others a dip.
Fat is likely your main fuel by now. Keep drinking water, and keep warm.
A longer fast. Electrolytes start to matter more.
Go gently, keep up water and electrolytes, and eat if you feel unwell.
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
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.
Privacy
No email, no login, no sign-up wall. Download the app and start.
Your fasts, check-ins, photos and notes are saved on your device. There is no StayFasted server holding them.
Replies to your check-ins are produced on your iPhone. What you write is not sent to a server.
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
The free app is a complete fasting timer. Pro adds the AI replies, the full history and the deeper tools.
Everything you need to start and finish a fast.
About $3.33 a month. Or $5.99 billed monthly. Cancel any time.
Everything in Pro, with one payment and no renewals.
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.
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.
No. There is no account and nothing to sign up for. Your fasting data is stored on your iPhone.
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.
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.
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.
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.
In the Settings app on your iPhone: tap your name, then Subscriptions. If you cancel, you keep what you recorded while you were subscribed.
Free on the App Store. No account, no sign-up.
Download for iPhone