See the useful window.
Understand your current boost without guessing from the feeling alone.
Use caffeine for performance. Protect your sleep.
Clarity models how caffeine behaves in your body, so you can time it for focus and output without wrecking your sleep.
Your caffeine, in context
Everything you need to time it better.
Know what reaches bedtime.
See the doses contributing to your projected bedtime impact.
Turn patterns into insight.
Connect caffeine, sleep and focus through Clarity Intelligence.
Start from a clear baseline.
Log each dose and let the day’s caffeine picture build from there.
A better caffeine strategy
Performance isn’t about more caffeine.
It’s about better timing.
Clarity turns each intake into a live model, helping you see the useful window and the caffeine that remains after the feeling fades.
The essentials
Frequently asked.
What does Clarity do?
Clarity is an iPhone caffeine tracker that models how caffeine rises and fades across your day. It helps you connect timing with focus, output and the sleep ahead.
How does Clarity estimate active caffeine?
Clarity applies a caffeine half-life model to the drinks you log. The result is an estimate of what may still be active, not a medical measurement.
What is Bedtime Impact?
Bedtime Impact projects how much caffeine may remain at your selected bedtime and identifies the logged doses contributing to that estimate.
Where is Clarity available?
Clarity is available for iPhone on the App Store and requires iOS 18 or later. It is built in the UK by Nexus Nexus Ltd.
Built in the UK. Used with intention.
Make caffeine work around your life.
See what is active. Use the window. Protect the night ahead.
View on the App Store