Stim Check

Track your intake, see your caffeine curve, and find out when you’ll actually be clear for sleep. Free, no ads, no sign-up.

You’re probably still caffeinated.

PreFix: Stim Check helps you track how much caffeine is still active in your system—and when you’ll actually come down.

Most people guess when caffeine wears off. This tool shows you.

Log your coffee, pre-workout, or energy drinks and visualize your caffeine levels over time based on your body weight and caffeine half-life.

See exactly when you drop below a sleep-safe threshold so you can better manage timing, performance, and recovery.

Features:

Log caffeine intake (coffee, pre-workout, energy drinks) Visualize your caffeine curve throughout the day See how much caffeine is still active in your system Get a “clear by” time for when levels drop Simple, fast, and easy to use

Built for lifters, athletes, and anyone trying to better understand their caffeine habits.

Free. No ads. No signup.

This app provides estimates based on average caffeine metabolism and is not medical advice.