Halflife: Caffeine Tracker

One question decides your sleep: how much caffeine will still be in your system at bedtime? Halflife answers it in three taps.

- Tap a drink (espresso 63mg, coffee 95mg, cold brew, matcha, energy, tea, custom)
- See your live caffeine curve for the whole day
- "At bedtime: 43mg. Sleep-safe." Or not
- Last-cup cutoff time, computed for you

The feature others skip: a PERSONAL half-life setting. Average is 5 hours, but oral contraceptives add ~50%, pregnancy roughly doubles it, slow metabolizers run 9+ hours. Generic curves are wrong by hours. Yours won't be.

Full drink library included free. No account. No ads. Works offline, so a crash can never eat your data.

Estimates for information only, not medical advice