Clue vs Stardust: how do they compare?
Clue and Stardust are both listed on HerFound, and both carry facts sourced from their own pages. Same for both: there is a free version. On selling data, the same for both: 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
 Clue |  Stardust | |
|---|---|---|
| What it is | A period tracker: cycle tracking with predictions for your period, PMS and ovulation. | 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 | $9.99/month or $39.99/year | $6.99/month, or $24.99 to $39.99/year |
| Selling personal data | Says it does not sell personal data. | 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 | You need an account to use it. | — |
| Where your data is kept | Your data is stored on the company's servers. | 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 | Germany | United States |
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 Clue does
Everyone with a cycle, Clue says, across life stages from a first period to perimenopause.
- 🩸 Period and cycle tracking with period, PMS and ovulation predictions
- 📝 Log symptoms, mood and other cycle experiences
- 🔄 Track your cycle even without menstrual bleeding
- 🌱 Clue Conceive mode with fertile window predictions (Clue Plus)
- 🤰 Pregnancy and perimenopause modes (Clue Plus)
- 💞 Clue Connect to share your cycle with another person (Clue Plus)
- ⌚ Connect a wearable for temperature and sleep data (Clue Plus)
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
Clue vs Stardust: common questions
Clue: there is a free version. Stardust: there is a free version.
Clue's paid plan is listed at $9.99/month or $39.99/year. 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.
Clue says it does not sell personal data. Stardust says it does not sell personal data. This is what each company states in its own policy, not an audit.
Clue: your data is stored on the company's servers. Stardust: your data is stored on the company's servers.