A calm, private period & cycle tracker made for girls and women everywhere. Predict your next period, ovulation and fertile window — all in your browser, all yours.
Enter a few details and Luna predicts your next period, ovulation day and fertile window. Saved safely on your device.
Everything stays on this device — nothing is uploaded.
Forecast your next period, ovulation day and fertile window based on your own cycle history.
No accounts, no servers. Your data lives only in your browser — you stay in control.
See your whole month at a glance with colour-coded period, fertile and ovulation days.
Log how you feel each day to spot patterns across your cycle over time.
Understand your average cycle length and where you are right now in real time.
Beautiful and fast on phone, tablet and desktop. Works even without internet.
Tap a mood to log it for today. Luna remembers it on your device.
No mood logged today yet.
Luna uses your last period start date and your average cycle length. Ovulation is estimated ~14 days before your next period, with the fertile window spanning the 5 days before plus ovulation day.
Yes. All data is stored locally in your browser using localStorage. Nothing is ever sent to a server, and there's no sign-up.
No. Luna is for awareness and education only. Predictions are estimates and should not be relied on to prevent or achieve pregnancy. Talk to a healthcare professional for medical advice.
Luna works best with regular cycles. With irregular cycles, treat predictions as rough guidance. Logging moods and dates over time helps you spot your own patterns.