Best Ovulation Tracker Apps in 2026

Flo's ovulation tracking uses AI algorithms trained on data from hundreds of millions of cycles. The predictions improve over time as you log more data — period dates, symptoms, mood, and sexual activity. After 3-4 cycles, most users report ovulation estimates that align closely with OPK results.

The app's biggest advantage for TTC is the seamless transition. Once you conceive, Flo switches to pregnancy mode with week-by-week tracking, symptom logging, and a massive medically-reviewed content library. You don't need to export data or start over with a new app. It's one continuous health record.

Flo's ovulation predictions are algorithm-based, meaning they estimate rather than confirm ovulation. If you have irregular cycles, PCOS, or other conditions that affect ovulation timing, algorithm-only predictions may be less reliable. For higher accuracy, temperature-based apps like Natural Cycles or Fertility Friend provide physiological confirmation.

Natural Cycles uses basal body temperature to detect the post-ovulation temperature shift that confirms you've ovulated. This is a fundamentally different approach from algorithm-only apps. Instead of predicting when ovulation should happen based on cycle history, it identifies when ovulation did happen based on your body's signals.

For TTC, this is valuable. The app identifies your fertile window with "red days" (fertile — good for trying) and "green days" (not fertile). Over time, it learns your unique pattern. The algorithm accounts for temperature fluctuations from illness, alcohol, and disrupted sleep, though these factors still reduce accuracy temporarily.

Natural Cycles requires daily commitment. Temperature must be taken at the same time each morning before getting out of bed. If you're consistent, the fertility data is superior to algorithm-only apps. If you're not a morning person or travel frequently, the discipline required may be frustrating. The subscription includes a compatible thermometer.

Clue's ovulation tracking takes the same science-first approach as its period tracking. The algorithm estimates ovulation based on your logged cycle data, and Clue Plus adds more detailed fertility predictions with probability windows. The app publishes peer-reviewed research using aggregate data, which gives its methodology more credibility than apps that don't disclose their algorithms.

Privacy is Clue's differentiator for ovulation tracking. Fertility data is among the most sensitive health information you can log. Clue stores everything in the EU under GDPR, has a clear no-data-selling policy, and the free tier works without ads. For women who want ovulation estimates without trading intimate health data, Clue is the safest mainstream choice.

Clue's ovulation predictions are algorithm-based, so the same limitations as Flo apply — estimates, not confirmation. Clue doesn't include a dedicated pregnancy mode, so once you conceive, you'll switch to a different app for pregnancy tracking.

Fertility Friend is the most data-intensive ovulation tracker available. It supports BBT charting, cervical mucus logging, OPK results, cervical position, and dozens of other fertility signs. The charting tools are more detailed than any competitor, which makes it the go-to for women who want to understand their cycle at a granular level.

The app uses multiple detection methods to pinpoint ovulation: temperature analysis, symptothermal method, OPK detection, and algorithm-based prediction. This layered approach catches ovulation even when individual signs are ambiguous. The community forums are active and full of experienced TTC users sharing chart interpretations.

The trade-off is complexity. Fertility Friend's interface looks like it was designed by data scientists for data scientists. The learning curve is steep. If you want a simple "tap and track" experience, this isn't it. But if you want to deeply understand your fertility patterns with maximum data, Fertility Friend is unmatched.

Ovia Fertility focuses specifically on helping women conceive. The app tracks periods, BBT, cervical mucus, OPK results, and intercourse timing, then provides a daily fertility score. The TTC coaching and insights are more focused than general-purpose trackers — Ovia tells you not just when to try, but offers tips to optimize your chances.

Like Ovia's pregnancy tracker, the fertility app is often available free through employer health benefits. The transition to Ovia Pregnancy is seamless once you conceive. The data logging is more granular than Flo or Clue but less complex than Fertility Friend.

Privacy concerns apply. The employer-sponsored model means your fertility data may be part of aggregate health reporting. If you're comfortable with that trade-off, Ovia's TTC features are strong. If data privacy around fertility is paramount, Clue or Natural Cycles are safer choices.