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⚡ Quick Picks
How We Evaluated These Apps
We looked at five things that matter most when you're actively trying to conceive:
- Prediction accuracy: Does the app rely on calendar math alone, or does it use real physiological signals like basal body temperature (BBT) and OPK results?
- TTC-specific features: Fertile window alerts, intercourse timing logs, partner sharing, pregnancy progression tracking.
- Data privacy: Where your data lives, who can see it, and whether the company has a history of sharing it. This matters more in 2026 than ever.
- Free vs paid value: What you actually get without paying and whether the premium tier is worth the upgrade.
- Ease of use: How quickly you can log data daily without it feeling like homework.
Apps that use only your period dates to predict ovulation are guessing. Apps that use BBT data, cervical fluid observations, and OPK results are detecting. If you're serious about TTC, pick an app that supports all three inputs — or at a minimum, BBT tracking.
The Best Fertility Apps, Ranked
Clue is the most well-rounded fertility app on the market. It combines clean design, solid science, and strong privacy protections. The free tier handles basic cycle tracking, while Clue Plus ($30/year) unlocks Conceive Mode with fertile window predictions up to 12 months out, BBT tracking, and expanded symptom logging.
What sets Clue apart is its editorial team. Their in-app articles are written and reviewed by reproductive scientists — not content farms. The app collaborates with research institutions including Oxford and Stanford, and their prediction algorithm has been validated in peer-reviewed studies. Being based in Germany means GDPR protections apply, and the company has publicly stated it will not share data with U.S. authorities.
- Clean, intuitive interface
- Conceive Mode with BBT integration
- GDPR privacy protections
- Science-backed prediction algorithm
- 75+ tracking categories
- Best features require Clue Plus
- No community forum
- Cloud-based data storage
- No wearable integration beyond Apple Health
Best for: TTC couples who want a polished, science-backed app with fertility-specific features and strong privacy.
Fertility Friend is the most data-rich fertility app available — and the most generous free tier of any app on this list. The free version includes advanced charting, BBT analysis, OPK logging, cervical fluid tracking, intercourse timing, and their pattern-detection algorithm. Premium adds pregnancy monitoring, early pregnancy sign analysis, and extended stats.
The trade-off is aesthetics. Fertility Friend looks like it was designed in 2012 — because it largely was. The interface is dense, chart-heavy, and not particularly intuitive for beginners. But for TTC veterans who want maximum data and don't mind a learning curve, nothing else comes close.
- Best free tier of any fertility app
- Advanced BBT charting and crosshairs
- 20+ years of algorithm refinement
- Active TTC community forums
- Custom data overlays and pattern analysis
- Dated interface and steep learning curve
- Can feel overwhelming for beginners
- No wearable integration
- Ads in the free version
Best for: Data-driven TTC users who want granular BBT charting and the best free fertility tracking available. Pair it with a BBT thermometer for best results.
Natural Cycles is the only fertility app that has received FDA clearance as a Class II medical device. Its algorithm analyzes daily BBT readings — either from its included thermometer or from compatible wearables like the Oura Ring and select Garmin watches — and identifies your fertile and non-fertile days with green (not fertile) and red (fertile/use protection) day labels.
While FDA clearance was originally for contraception (93% typical use, 98% perfect use), the app also has a dedicated Plan Pregnancy mode. In March 2026, Garmin added Natural Cycles integration for five smartwatch models, making overnight temperature tracking effortless. The company raised $55 million in its Series C and is profitable.
- Only FDA-cleared fertility app
- Oura Ring + Garmin wearable integration
- Clear green/red day system
- No data selling (stated policy)
- Plan Pregnancy mode included
- Most expensive app at $100/year
- No free tier (30-day trial only)
- Requires daily BBT measurement
- Less effective for very irregular cycles
Best for: Couples who want medically validated predictions and are willing to pay for them. Especially strong for those who already own an Oura Ring or compatible Garmin watch.
Flo is the world's most popular period and fertility app with over 77 million monthly users. It offers AI-powered cycle predictions, ovulation tracking, pregnancy mode, and a content library curated by 100+ medical professionals. The free version covers basic cycle and ovulation tracking; Premium adds personalized insights, partner sharing, and advanced analytics.
Flo's strength is accessibility — the interface is polished and beginner-friendly. Its weakness is its privacy history. In 2021, Flo settled with the FTC over allegations it shared sensitive user health data with Facebook and Google without consent. The company subsequently launched Anonymous Mode, which allows users to use the app without providing personal identifiers. Still, the settlement is worth knowing about.
- Beautiful, beginner-friendly interface
- AI-powered cycle predictions
- Pregnancy and partner modes
- Extensive health content library
- Anonymous Mode available
- FTC data-sharing settlement in 2021
- BBT features limited compared to FF
- Premium required for best insights
- Cloud-based data storage
Best for: Beginners who want an approachable first fertility app with broad content. Turn on Anonymous Mode for better privacy.
Glow stands out for its community features and the breadth of its ecosystem. The main Glow app handles ovulation and fertility tracking with a daily fertility score. Nurture handles pregnancy. Eve covers sexual health. The active community forums mean you're never tracking alone — which can be a genuine emotional lifeline during TTC.
The tracking interface logs over 40 data points including BBT, cervical mucus, OPK results, medications, and mood. Glow also offers a unique Fertility Calculator that aggregates data across users to provide statistical predictions. The free version is functional for basic tracking; Premium unlocks charts, comparisons, and advanced insights.
- Active TTC community and forums
- Daily fertility score
- 40+ trackable data points
- Companion app ecosystem (Nurture, Eve)
- Prediction accuracy mixed with irregular cycles
- Community moderation inconsistent
- US-based data storage
- Frequent upsell prompts
Best for: TTC users who value community support alongside tracking. Good companion to use with ovulation test strips.
Ovia is one of the few fertility apps that's completely free with no premium paywall. It offers daily fertility scores, fertile window predictions, BBT and cervical fluid tracking, and access to over 2,000 expert articles on reproductive health. Ovia also has separate apps for pregnancy (Ovia Pregnancy) and parenting (Ovia Parenting), so you can transition seamlessly.
The major caveat: Ovia is primarily offered through employers as a workplace health benefit. While the consumer app is free, the company's business model involves providing aggregate (de-identified) health data to employers. If your employer offers Ovia through a benefits program, your employer may receive anonymized usage reports. This isn't necessarily a dealbreaker, but it's something to understand before signing up.
- Completely free, no paywall
- Daily fertility score system
- 2,000+ expert health articles
- Seamless pregnancy transition
- Employer-connected business model
- Aggregate data shared with employers
- Less precise than BBT-focused apps
- Interface less polished than Clue or Flo
Best for: Budget-conscious TTC users who want a free app with no feature restrictions and don't mind the employer-benefit model.
Euki is the most privacy-respecting fertility app available. Created by a nonprofit, it requires no account creation — just a PIN. All data is stored locally on your device and is never uploaded to any server. No cloud. No third parties. No way for anyone — including Euki itself — to access your information.
The trade-off is functionality. Euki's cycle predictions are basic — it uses calendar-based estimates rather than BBT-powered algorithms. The fertile window predictions are less precise than apps like Natural Cycles or Fertility Friend. But in a post-Dobbs landscape where reproductive data has legal implications, Euki offers something no other app can: genuine data sovereignty.
- 100% on-device data storage
- No account required (PIN only)
- Nonprofit, no advertising model
- Cannot be subpoenaed from cloud
- Calendar-only ovulation predictions
- No BBT or OPK integration
- Lose PIN = lose all data
- Minimal community features
Best for: Anyone who prioritizes data privacy above all else, particularly in states with restrictive reproductive legislation.
Premom pairs with Easy@Home ovulation test strips and uses your phone camera to photograph and analyze OPK results, predicting your LH surge. This photo-based OPK analysis is its standout feature and is genuinely useful — no squinting at test lines.
However, Premom carries serious privacy baggage. In 2023, the FTC fined its parent company Easy Healthcare $100,000 for sharing user health data — including fertility and pregnancy information — with third-party advertisers and two companies in China, despite privacy policies that explicitly promised it wouldn't. The company paid an additional $100,000 to state attorneys general and nearly $1 million total including class action settlements.
⚠️ What the FTC Found
The FTC complaint documented that Premom shared identifiable health data including menstrual cycle dates, fertility status, and pregnancy information with AppsFlyer, Google, and Chinese analytics companies Umeng (owned by Alibaba) and Jiguang — all without user consent. The app also collected precise geolocation data. Premom has since been barred from sharing health data for advertising and is required to obtain consent for any third-party data sharing.
- Photo-based OPK analysis is convenient
- Pairs with affordable Easy@Home strips
- Inexpensive premium tier
- FTC fine for sharing health data
- Data shared with companies in China
- Deceptive privacy policy history
- Trust difficult to rebuild
Our take: The OPK photo analysis is genuinely useful technology, but given the documented privacy violations, we recommend using Easy@Home test strips with a different app for logging results.
Side-by-Side Comparison
| App | Price | BBT | OPK | FDA | Privacy |
|---|---|---|---|---|---|
| Clue Plus | $29.99/yr | ✓ | ✓ | ✗ | 🟢 GDPR |
| Fertility Friend | Free | ✓ | ✓ | ✗ | 🟡 Cloud |
| Natural Cycles | $99.99/yr | ✓ | ✓ | ✓ | 🟢 No selling |
| Flo | Free/$49.99/yr | ✓ | ✓ | ✗ | 🟡 FTC 2021 |
| Glow | Free/$47.99/yr | ✓ | ✓ | ✗ | 🟡 Cloud |
| Ovia | Free | ✓ | ✗ | ✗ | 🟡 Employer |
| Euki | Free | ✗ | ✗ | ✗ | 🟢 On-device |
| Premom | Free/$19.99/yr | ✗ | ✓ (photo) | ✗ | 🔴 FTC 2023 |
What Actually Makes You More Fertile: The App or the Tracking?
Here's the honest truth: no app makes you more fertile. What a good app does is help you identify your fertile window more accurately so you can time intercourse better.
A 2020 study in the journal BMJ Sexual & Reproductive Health found that fewer than one in five women using fertility apps could correctly identify their fertile window. The apps that performed best were those that used physiological data — BBT and cervical mucus — rather than calendar-only predictions.
The real value stack for TTC couples isn't the app alone — it's the app plus the hardware:
- A BBT thermometer (1/100th degree precision, $10–15) for detecting ovulation after the fact
- OPK strips ($12–18 for a 50-pack) for predicting ovulation 12–36 hours ahead
- A fertility app that combines both data streams into a coherent picture
Our $30 TTC Tech Setup
Download Fertility Friend (free). Buy a BBT thermometer (~$12) and a 50-pack of OPK strips (~$16). Log your BBT every morning before getting out of bed, start OPKs around cycle day 10, and track cervical fluid daily. Total cost: about $28. This setup gives you the same core data as a $300/year wearable-plus-app combination.
A Word About Privacy in 2026
Fertility data is among the most sensitive personal information you can generate digitally. In the wake of the Dobbs decision, reproductive health data has taken on legal dimensions that didn't exist before 2022. Several states have pursued or considered laws related to reproductive health data, and law enforcement agencies have sought app data in investigations.
Here's what to consider when choosing a fertility app:
- Where is your data stored? On-device (Euki) vs cloud-based (most others). Cloud data can potentially be subpoenaed.
- Where is the company based? EU-based companies (Clue in Germany, Natural Cycles in Sweden) fall under GDPR, which offers stronger protections than US privacy law.
- Has the company been in trouble? Both Flo (2021) and Premom (2023) have faced FTC actions over data sharing practices.
- Does the app offer anonymous use? Flo's Anonymous Mode and Euki's PIN-only access offer different approaches to de-identification.
If privacy is your primary concern, use Euki for tracking and pair it with physical OPK strips and a BBT thermometer for the actual fertility data.
The Bottom Line
For most TTC couples, the decision comes down to three options:
- Want free and powerful? Use Fertility Friend. Accept the dated interface and gain the most comprehensive charting available.
- Want polished and private? Use Clue Plus at $30/year. Best balance of design, science, and GDPR-backed privacy.
- Want medical-grade validation? Use Natural Cycles at $100/year. Only FDA-cleared option, wearable-integrated, clinically validated.
Whichever app you choose, pair it with a BBT thermometer and OPK strips. The hardware matters more than the software — the app is just the dashboard.
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