Fast1. Add to your Home Screen
Open this link in Safari. Tap Share → Add to Home Screen, enable Open as Web App if shown, then tap Add.
Do this before your first real fast: the Home Screen app can save data separately from Safari.
YOUR OWN RHYTHM
A little time for yourself.
16 hours fasting. 8 hours for meals.
Ready when you are16 : 8
FASTING GOAL16:00:00Start at a time that suits you
16-HOUR GOAL
Your last 7 days
A filled circle means a completed 16-hour goal, by finish date.
Made for everyday life
Enter yesterday’s start time, close the app, and come back whenever you like.
YOUR PROGRESS
Every fast has a story.
Your saved records, kept on this device.
0Completed fasts
—Average duration
016-hour goals
Last 7 completed fasts
Saved fasts
Tap a record to edit its times, mood, or notes. Capacity: 2,000 records. Export backups to keep an extra copy.
MAKE IT YOURS
At home on your iPhone.
No subscription or ads in this tracker.
2. Prepare for offline use
Open Fast16 from its Home Screen icon once while online. Wait for the Offline ready badge above.
Then turn on Airplane Mode, close and reopen Fast16, and check that the timer and history open. After this check, you can start, end, and edit fasts without a connection.
Checking offline storage…
3. Use your own start time
Tap Start a fast, enter the date and time you started, then save. Tap Started · Edit to correct it later.
The timer keeps counting beyond 16 hours until you end it. Ending a fast saves it and starts an 8-hour eating window. You choose when to start the next fast.
Reminders that work offline
For an alert while your phone is locked or this app is closed, set an alarm in the iPhone Clock app for the goal time shown on your timer.
Fast16 does not send background notifications. Its timer updates from saved times whenever you reopen it.
Keep a backup
Your records stay in this app’s storage on this device. They do not sync to other devices. Removing the app or clearing website data can erase them.
Save the backup in Files. Restoring replaces the records currently in this copy of the app.
A personal timing tool, inspired by Zero’s fasting workflow. Not affiliated with Zero. Initial installation and app updates need internet; saved timing and records work offline once prepared. No health integrations or physiological predictions.