Track your fasts. Understand the science. Own your health.
Built for beginners and experienced fasters alike. Science-backed body phase tracking tells you exactly what's happening inside.
One-tap start with a beautiful live progress ring. See your elapsed time, target goal, and current body phase at a glance.
Choose from popular plans like 16:8, 18:6, 20:4, OMAD, and extended fasts up to 72 hours. Or create your own custom schedule.
Understand what your body is doing during each stage of your fast, from glycogen depletion to ketosis to autophagy.
Stay motivated with fasting streaks, weekly summaries, and historical stats. See your consistency and improvement over time.
Electrolyte reminders, safety check-ins, and guided protocols keep you safe during longer fasting periods.
Log your weight alongside your fasts. Visualize trends with overlay charts that connect your fasting habits to real results.
OneFast is free to use forever. Unlock advanced tools with Premium when you want to go deeper.
Available on iOS and Android. Free to download, no account required.