Flo vs Stardust: how do they compare?
Flo and Stardust are both listed on HerFound, and both carry facts sourced from their own pages. Same for both: there is a free version. Flo: says it does not sell personal data for money; Stardust: says it does not sell personal data. Last checked Nov 11, 2026.
Updated . We don't pick a winner or publish ratings. This sets out what each company says, side by side.
Side by side
 Flo |  Stardust | |
|---|---|---|
| What it is | A period and ovulation tracker: predictions plus personalized health insights. | A privacy-first period tracker: cycle predictions, moon phases and sharing with friends or a partner. |
| Price model | Freemium | Freemium |
| Platforms | iOS, Android | iOS, Android |
| Free version | There is a free version. | There is a free version. |
| Paid plan | $1.99 to $59.99 | $6.99/month, or $24.99 to $39.99/year |
| Selling personal data | Says it does not sell personal data for money. | Says it does not sell personal data. |
| Advertising | Says some data is used or shared for advertising. | Says some data is used or shared for advertising. |
| Account | Creating an account is optional. | — |
| Where your data is kept | Offers an anonymous mode: data is stored on its servers without your name or email. | Your data is stored on the company's servers. |
| Deleting your data | You can delete your data or account from inside the app. | You can delete your data or account from inside the app. |
| Company based in | United Kingdom | United States |
| Apple Watch | Has an Apple Watch app. | — |
Sources: each app's own privacy policy, help pages and US App Store listing. Open either app to read the exact passage behind each line and the date we checked it. “—” means we have not sourced that fact yet. This is what each company states, not an audit of what it does.
What Flo does
People tracking their periods, ovulation, pregnancy and perimenopause; Flo describes itself as a women's health app.
- 🩸 Period and cycle tracking that predicts your next period
- 🌱 Ovulation and fertile-day tracking for when you're trying to conceive
- 🤰 Week-by-week pregnancy tracking
- 🌙 Perimenopause symptom information and support
- 💞 Flo for Partners: share your cycle information with a partner (Premium)
- 🕶️ Anonymous Mode: no name or email linked to your health data
- 🤖 Premium extras: a health assistant chatbot and personalised health reports
What Stardust does
Anyone with a cycle, regardless of gender identity, as Stardust's FAQ puts it.
- 🩸 Period and cycle tracking with predictions
- 📝 Log symptoms, moods, cravings and basal body temperature
- 🌱 Fertility and ovulation tracking, with a trying-to-conceive setting
- 🤰 Pregnancy mode with daily forecasts and a week-at-a-glance view
- 🌙 Your cycle shown alongside lunar phases
- 🔮 Horoscope and tarot content on Stardust Super
- 💞 Share your cycle with friends, or with a partner in Partner Mode
- ⌚ Connects to Apple Health and Oura Ring data
Flo vs Stardust: common questions
Flo: there is a free version. Stardust: there is a free version.
Flo's paid plan is listed at $1.99 to $59.99. Stardust's is listed at $6.99/month, or $24.99 to $39.99/year. Prices change and differ by country; each listing shows where and when we read them.
Flo says it does not sell personal data for money. Stardust says it does not sell personal data. This is what each company states in its own policy, not an audit.
Flo: offers an anonymous mode: data is stored on its servers without your name or email. Stardust: your data is stored on the company's servers.