Intermittent: Fasting Timer

The intermittent fasting timer that shows which fasting phase you have likely reached, from fat burning lipolysis to ketosis and autophagy, based on how long you have fasted. Ad free. No account required.

Most fasting apps give you a countdown clock and a streak to protect. Intermittent does something different. It maps your hours fasted to the phases research describes, and explains the science behind each one with cited primary sources, not marketing copy. If you have ever wondered how to track fasting properly, or what is likely happening during a fast, this is the fasting tracker built for that question.

WHY FASTING WORKS

Intermittent fasting works because of what happens between meals, not just the absence of food. As your fast progresses, your body moves through distinct phases: burning through glucose reserves, shifting into fat burning lipolysis, entering ketosis, and eventually triggering autophagy, the cellular repair process linked to longevity and metabolic health. Understanding these transitions is what separates intentional fasting from guesswork. Intermittent maps every stage so your goals are grounded in biology, not motivation.

KEY FEATURES

PHASE AWARE FASTING TIMER
A live timer that maps your fast to six phases: Fed, Early Fasting, Lipolysis, Ketosis, Autophagy, and Deep Fast. Each phase links to a free science article with primary sources cited.

EVERY FASTING PROTOCOL, ONE APP
Supports 12:12, 14:10, 16:8, 18:6, 20:4, OMAD (One Meal A Day), 36 hour, 48 hour, and 72 hour fasts.

FREE FASTING SCIENCE LIBRARY
A full library of fasting articles covering intermittent fasting, ketosis, autophagy, insulin response, and more. No subscription. No account. No paywall.

SMART HYDRATION TARGET
A science backed hydration goal that adapts to your weight, sex, age, and fasting duration.

WEIGHT AND PROGRESS TRACKING
Log your weight after each fast and track trends over time. Includes streak heatmap, phase reach history, and estimated fat vs glucose energy usage.

PRIVATE CIRCLE AND END OF FAST REFLECTION
Share your fast with a small private group. Applause only responses. No comparison. No gamification.

HOME SCREEN WIDGET AND CROSS DEVICE SYNC
Keep your fasting timer visible with a home screen widget. Your data syncs across devices privately without third party trackers.

EATING WINDOW, REMINDERS AND RECAPS
See your eating window after each fast, with an optional heads-up before it closes. Set your usual start time for a gentle reminder. Look back on each month and year with a recap you can share.

WHO IT IS FOR

Intermittent is built for adults who want to understand fasting, not be coached through it. If you follow research on metabolic health, read about longevity, or want a fasting routine grounded in biology rather than points or streaks, this app is for you. Suitable for both beginners and experienced fasters.

HOW IT WORKS

Choose your fasting protocol, from 12:12 to extended fasts
Start your timer and see which phase you have likely reached
Tap any phase to read the science and log your reflection at the end

No account required to start. No subscription required to access the library.