You already fast every night.
FastMode makes it count.

A simple intermittent fasting tracker that shows what your body is doing — hour by hour. Free to start.

Download Free
FastMode app — ring timer showing fasting phase

Did you know you're already fasting right now?

If your last meal was at 7pm and you woke up at 7am, you just completed a 12-hour fast. FastMode picks up where you left off — and shows you what your body is doing while you sleep.

Three phases.
One ring.
Total clarity.

01

Start your fast

Set your eating window once. FastMode does the rest — tracking your fast from there.

At 12 hours, you enter Fat Burn. At 16, Peak Fat Burn. Your ring timer changes color as your body shifts gears — no guessing required.

03

Build the habit

Your streak grows every day you complete a fast. Life happens? Streak Freeze has your back. No all-or-nothing pressure.

Everything you need.
Nothing you don't.

Live Metabolic Phases

Your ring timer changes color as your fast deepens. Know exactly where you are, always.

Fasting Fat Burn 12h Peak Fat Burn 16h

Your Personal Goal Date

Enter your weight and goal once. FastMode calculates a realistic date — not "a few months," but the date.

No Calorie Counting

Track your eating window, not every gram. It's about when you eat, not what.

Streak System

Build a daily fasting habit. The longer your streak, the more you want to protect it.

Streak Freeze

Life happens. Freeze your streak for one day without breaking it. No all-or-nothing pressure.

Smart Notifications

Get notified when you hit Fat Burn, when your eating window is closing, or when your streak is at risk. Contextual, never spammy.

Weight Tracking & Trends

Log your weight daily. Watch the trend line move toward your goal. Over time, the data tells a story that the scale alone never could.

This isn't a trend.
It's biology.

Intermittent fasting triggers measurable metabolic changes — not theories, not influencer claims. After 12 hours without food, your body begins burning stored fat as its primary fuel.

After 16 hours, it enters peak fat-burning mode and begins autophagy — the cellular cleanup process recognized by the Nobel Prize in 2016.

FastMode shows you exactly when these thresholds happen. In real time. On your wrist.

16:8 The most-studied intermittent fasting protocol
12h When fat burn begins
16h Peak fat burn & autophagy kick in
Nobel
2016
Autophagy research awarded Nobel Prize in Physiology

Referenced from Harvard Health Publishing and peer-reviewed research on intermittent fasting and metabolic health.

"Other fasting apps made me feel like I failed every time I missed a day. FastMode feels different — and Streak Freeze means I don't have to be perfect."
Monika

Monika, 34

Your body already knows how to fast.
FastMode just makes it visible.

Free to download. Available on iPhone and Android.

Download Free