Clue vs Flo vs Lulu: which period tracker fits you?
Clue and Flo are both big, account-based trackers. Clue leans on science, research partnerships and EU privacy law; Flo leads on content, pregnancy and partner features. Lulu is a smaller iPhone app built around mood: it shows how you usually feel in each phase, needs no account and keeps cycle data on your iPhone.
Clue vs Flo vs Lulu at a glance
Clue and Flo facts are from their US App Store listings, help centers and public records, checked October 2026. Lulu facts are from our own product.
| Clue | Flo | Lulu | |
|---|---|---|---|
| Platforms | iPhone, Android; works with Apple Watch, Oura, WHOOP and others | iPhone, Apple Watch, Android | iPhone; imports Apple Watch wrist temperature |
| Tracking | 200+ symptoms and experiences | 70+ symptoms and moods | One-tap mood check-in, symptoms as bunny drawings |
| Forecasts | PMS, cramps and energy-dip forecasts | Personalized insights (Premium) | Mood forecast by cycle day, heads-up before harder days |
| Life stages | Conceive, pregnancy, perimenopause modes | Pregnancy Mode, perimenopause tools | Perimenopause mode; no pregnancy mode |
| Partner sharing | Not listed on its US App Store page | Flo for Partners | Partner sync via private iCloud link |
| Content | 400+ articles; university research partners | Large library, expert videos, Symptom Checker | Short phase guides |
| Account | Yes | Yes, with Anonymous Mode | No account |
| Privacy notes | Berlin company under GDPR; App Store label lists Identifiers as used to track you | App Store label lists Purchases, Location, Identifiers and Usage Data as used to track you; FTC order in 2021 | No Lulu server receives your cycle data |
| Price model | Free plus Clue Plus | Free plus Flo Premium | 3-day free trial, then yearly Lulu Plus |
Clue vs Flo: the short version
Clue feels like a science notebook. It's precise, inclusive ("for everyone with a cycle"), and backed by research partnerships with universities. Its privacy pitch is built on being a Berlin company under GDPR, and it says it never sells health data. Clue Plus adds perimenopause mode and deeper analysis.
Flo feels like a health magazine with a tracker inside. It has the bigger content library, a polished pregnancy experience and partner sharing. Its privacy history is heavier: an FTC order in 2021 over sharing health data with analytics firms, and a 2025 jury verdict against Meta over data collected from Flo users. Flo has since added Anonymous Mode.
Where Clue is stronger than Lulu
- Science partnerships. Clue works with universities and researchers, and its articles are long and well sourced.
- Breadth of tracking. 200+ options, including sex, birth control, discharge, sleep and much more.
- Wearables. Clue can layer data from several wearables, not just Apple Watch.
- Android. Clue runs on Android; Lulu is iPhone only.
- Conceive and pregnancy modes. Lulu doesn't offer either.
Where Lulu is different
- Mood first. Lulu turns a one-tap daily check-in into a picture of how you usually feel on each cycle day, then gives you a heads-up before harder days.
- No account, no server. Your cycle data stays on your iPhone. We never receive it.
- Partner sync that shows your phase, plus your mood forecast if you choose, never your symptoms, notes or history.
- Doctor-ready PMS chart you can export as a CSV for appointments.
- Warmth. Lulu the bunny changes with your phase. It's meant to feel kind, not clinical.
If you want to understand your body in detail, Clue. If you want everything in one big app, Flo. If you want to understand your ups and downs and plan around them, Lulu.
Who each app suits
| Choose Clue if… | Choose Flo if… | Choose Lulu if… |
|---|---|---|
| You like data, detail and science | You want content, community and pregnancy | You want to see your mood pattern |
| You use Android or several wearables | You want partner sharing on Android | You want no account and on-device data |
| You want EU-law privacy | You want a free tier with lots inside | You're fine with a 3-day trial then yearly |
A note on accuracy
All three apps predict periods and fertile windows from your logged cycles; none of them can know exactly when you'll ovulate without a test or temperature data. Predictions get better the more cycles you log, and are less reliable for irregular cycles. Read how accurate period trackers are for the details, and Clue alternatives for more options.
Frequently asked questions
Is Clue better than Flo?
Neither is better for everyone. Clue is stronger on science and EU privacy; Flo is stronger on content, pregnancy and partner features.
Is Clue safer than Flo for privacy?
Clue is a Berlin company under GDPR and hasn't faced an FTC order like Flo did in 2021. Both are account-based, and both list some tracking data on their App Store labels.
Does Lulu work on Android?
No, Lulu is an iPhone app. Clue and Flo both have Android versions.
Can I use Clue or Lulu as birth control?
No. Neither the standard Clue app nor Lulu is a method of contraception.
Sources
- Clue Period & Cycle Tracker on the App Store (US)
- Clue: Privacy
- Flo Cycle & Period Tracker on the App Store (US)
- FTC: FTC Finalizes Order with Flo Health (June 2021)
This page is for information only and isn’t medical advice. If something worries you, please talk to a doctor.
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