The two biggest period trackers, head to head — and one free option that beats both.
If you're choosing a period tracker, Flo and Clue are the two names that come up most. Both are well-designed, widely used, and genuinely useful. But they're also both moving toward paywalls — and one of them has had serious data privacy problems. Here's the honest comparison.
| Feature | Flo | Clue | WomensPal |
|---|---|---|---|
| Price | Free / $39.99/yr | Free / $39.99/yr | 100% Free |
| Cycle tracking | ✓ | ✓ | ✓ |
| Ovulation tracking | Limited free | Limited free | ✓ Free |
| Pregnancy mode | Premium only | Premium only | ✓ Free |
| Postpartum mode | ✗ | ✗ | ✓ Free |
| Symptom logging | ✓ | ✓ | ✓ |
| Phase-based insights | Premium | Premium | ✓ Free |
| Privacy | FTC settlement 2021 | GDPR-compliant | No data selling |
| Ads (free tier) | Yes | No | No |
| Kick counter | ✗ | ✗ | ✓ |
| Contraction timer | ✗ | ✗ | ✓ |
Flo is the world's most downloaded period tracker with over 420 million users. Its content library is massive — thousands of medically reviewed articles on everything from PMS to menopause. The AI-powered predictions are solid, and the community forums are among the most active anywhere.
But there are real problems. In 2021, Flo settled with the FTC after sharing intimate health data — including period dates, pregnancy status, and fertility information — with Facebook and Google, without user consent. Flo has since added an "Anonymous Mode" to address privacy concerns, but users have to opt in to activate it.
The free tier is now quite limited. To access health insights, cycle analysis, symptom reports, and pregnancy mode, you need Flo Premium at $39.99/year ($11.49/month if billed monthly).
Best for: Women who want the most popular app, aren't worried about data privacy, and are willing to pay $40/year.
Clue is developed in Berlin and takes a noticeably different approach to period tracking. Where Flo leans into wellness and lifestyle content, Clue focuses on the science of cycles. The interface is clean and deliberately non-pink, which many users appreciate.
Clue's privacy credentials are stronger than Flo's — it's GDPR-compliant, stores data on European servers, and has no documented history of sharing health data with advertisers. The free tier is more functional than Flo's, but pregnancy mode, wearable sync, health history export, and deeper analysis require Clue Plus at approximately $39.99/year.
Best for: Science-minded women who value privacy over a slick UI and are happy to pay for premium features.
WomensPal launched to give women a period tracker that doesn't choose between features and privacy, or put the best features behind a paywall. The result is a completely free app that does more than either Flo or Clue in their paid tiers.
You get full cycle tracking, ovulation and fertile window prediction, a pregnancy mode (with kick counter and contraction timer that neither Flo nor Clue have), postpartum recovery tracking, cycle syncing, phase-based daily insights, and doctor-ready PDF reports. No subscription. No ads. No data selling.
Everything Flo Premium and Clue Plus offer — plus pregnancy tracking with kick counter and contraction timer — completely free.
Start free — no subscription →If you want the most popular app and you're happy to pay: Flo. If privacy matters and you'll pay for it: Clue. If you want everything both offer for free, with better pregnancy features: WomensPal.
Clue wins on privacy (GDPR-compliant, no data-selling history). Flo wins on content volume and global popularity. But both charge ~$40/year for their best features. WomensPal offers everything both apps offer — for free.
Flo settled with the FTC in 2021 for sharing sensitive health data with Facebook and Google without user consent. The company has added an Anonymous Mode since then, but the trust deficit remains.
Clue has a free tier with basic tracking. Clue Plus costs ~$39.99/year and unlocks pregnancy mode, wearable sync, health history, and deeper analysis.
WomensPal is the best free alternative to Flo — same features (cycle tracking, ovulation, pregnancy mode, symptom logging) without the subscription fee or data concerns.