Hazel is a private period and cycle tracker that keeps everything on your phone. No account, no cloud, no ads, and no analytics. What you log stays in the app, on your device — and you can prove it: turn on Airplane mode and Hazel keeps working, because it never needed a connection.
Most period apps quietly send sensitive reproductive-health data to third parties. Hazel is built the opposite way. There is no sign-in, no server, and no tracking code anywhere in the app. "No data collected" isn't a promise here — it's the architecture.
WHAT YOU CAN DO
- Log your period in a tap: spotting, light, medium, heavy, or none.
- Track symptoms, mood, and a private note for any day.
- See where you are at a glance: cycle day, current phase, and a calendar of your history.
- Get honest predictions. Hazel shows your next period as a range, not a false-precise single day, and the range widens or tightens based on how regular your cycles actually are.
- Estimate your fertile window and ovulation — or turn it off entirely if you'd rather not see it.
- Set or correct your cycle start date with a simple in-app calendar.
PRIVATE BY DESIGN
- No account and no sign-in, ever.
- Nothing leaves your phone unless you export it yourself.
- No ads, no trackers, no analytics, and no AI guessing about your body.
- No streaks and no pressure to log every day.
- Works fully offline.
MADE TO FEEL CALM
Hazel is deliberately quiet. Warm, editorial design, a discreet name that reveals nothing on your home screen, and microcopy written by humans — not the usual clinical or data-hungry period app. Choose from several colour themes, light and dark.
INSIGHTS
Once you've logged a cycle or two, Hazel shows your averages, your cycle history, and how steady your cycles are.
HAZEL PLUS (optional, one-time)
Hazel is free and complete — you never have to pay to track your cycle. If you'd like to support an app with no ads and no data-selling, a single one-time purchase (no subscription) unlocks Hazel Plus:
- Encrypted backups, locked with your own passphrase.
- Pattern insights: which symptoms cluster around your period, your mood patterns, and whether your cycle length is steadying.
- Small future touches, no upsells.
YOUR DATA, YOUR CONTROL
Export a plain backup any time, or an encrypted one with Plus. Delete everything from the app whenever you want. There is no copy of your data anywhere else, because there is nowhere else.
A NOTE
Hazel describes what you log and estimates from it. It is not a contraceptive method and not medical advice. For questions about your health, talk to a clinician.