A free Natural Cycles alternative for cycle tracking
HerFlow tracks your period, moods, and cycle phases for free, with no account, no subscription, and no temperature readings.
| Feature | HerFlow | Natural Cycles |
|---|---|---|
| Free to track your cycle | YesNo ads, no time limit | NoPaid subscription required |
| Use without an accountNo email, phone number, or sign-in | Yes | NoEmail account |
| Data used to track youApp Store privacy label | None | YesContact info |
| Works without temperature readings | YesLog periods, moods, and symptoms | NoUses a thermometer or wearable |
| Partner sharing without an accountNo sign-up for anyone | YesA random code is all it takes | NoNC° Partner View uses NC° accounts |
HerFlow is not birth control. Natural Cycles is FDA-cleared as a birth control method. HerFlow is for understanding your cycle and must not be used to prevent pregnancy.
Checked on September 25, 2026, against the Natural Cycles App Store listing and Natural Cycles' help pages. Privacy labels are self-reported by each developer. See how HerFlow compares with Flo, Clue, Stardust, and Natural Cycles in the full comparison.
Natural Cycles is a trademark of its owner, which is not affiliated with HerFlow.
Why people choose HerFlow for tracking
Free for your own cycle
Tracking your own cycle is free, with no time limit and no ads. Only the person following someone else pays for People, after a free 7-day trial.
Nothing to measure
No thermometer, no wearable, no morning routine. Log your period, moods, and symptoms, and HerFlow shows your phase and what's next.
No account, even when you share
HerFlow works the moment you open it, and a partner follows your cycle with just a random code. Neither of you creates an account.
Getting started takes a minute
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Get HerFlow
Download it free from the App Store. There is nothing to sign up for.
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Add your cycle
Enter the start of your last period and your usual cycle length, and HerFlow shows your phase right away.
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Share, if you want to
Give your random code to your partner or someone you trust, and they follow your cycle with tips on how to support you.
Is HerFlow a free alternative to Natural Cycles?
For tracking your cycle, yes. HerFlow is free for your own cycle with no time limit, needs no account, and declares no data used to track you on its App Store privacy label. It predicts your period and fertile window, logs moods and symptoms, and explains each phase of your cycle in plain language.
Can I use HerFlow as birth control?
No. Natural Cycles is FDA-cleared as a birth control method; HerFlow is not a medical device and not a contraceptive. Its fertile-window and ovulation estimates are for understanding your cycle, not for preventing or planning a pregnancy. Talk to a healthcare professional about contraception.
Do I need a thermometer or wearable to use HerFlow?
No. HerFlow works from the periods, moods, and symptoms you log, so there is nothing to measure each morning and no device to buy.
Try HerFlow on your iPhone
Free to track your own cycle. No account, no ads, no analytics.