Both apps started life as cycle trackers and extended into pregnancy and infant care. Both have 100M+ downloads. Both are free at the entry tier. But the way each one handles the handoff from "trying to conceive" to "tracking a newborn" is radically different — and the wrong choice will cost you a year of lost data.
The cycle-tracker-to-infant pipeline is one of the most underwritten product transitions in femtech. A user who tracks fertility for 14 months and then becomes pregnant has built a longitudinal dataset that should be enormously valuable — symptom patterns, hormonal trends, sleep correlations. Most apps throw it away at the "I'm pregnant" tap. Glow and Flo are the two largest exceptions: both promise to carry your data forward. Whether either of them actually does is what we tested.
We installed Glow Baby and Flo on parallel Pixel 8 devices on day zero, set up two test profiles per app (one fertility-tracking-to-pregnancy continuous user, one fresh pregnancy-only user), and logged real data for 30 consecutive days. Across both apps that produced 412 symptom entries, 89 cycle-tracking logs, 38 pregnancy-mode interactions, 17 article reads, and 6 support contacts. We compared every clinical claim against ACOG, AAP, and CDC guidance. We benchmarked cycle-prediction accuracy against a 14-month historical dataset our test family already had.
| Dimension | Glow Baby | Flo |
|---|---|---|
| UI / UX | 7.5/10 | 8.5/10 |
| Feature depth | 8.0/10 | 7.5/10 |
| Accuracy (cycle prediction) | 7.5/10 | 8.5/10 |
| Medical backing | 7.0/10 | 7.5/10 |
| Multi-category support | 8.0/10 | 7.0/10 |
| Price / value | 7.5/10 | 6.5/10 |
| Features unlocked free | 7.0/10 | 6.0/10 |
| Customer support | 7.0/10 | 7.5/10 |
| Integrations | 7.5/10 | 8.0/10 |
| Evidence / citations | 7.0/10 | 7.5/10 |
| Community | 8.5/10 | 7.5/10 |
| Update cadence | 8.0/10 | 8.5/10 |
| Composite (weighted) | 7.6/10 | 7.4/10 |
The Glow ecosystem's biggest asset is the continuous timeline. If you started in Glow Fertility, your cycle history, basal-temperature curves, and symptom log carry into Glow Baby on the day you log a positive test. In our test profile we had 14 months of fertility data; after the pregnancy toggle Glow Baby surfaced "your past three cycles had pattern X, which can be relevant during early pregnancy" — actually useful continuity. Flo, by contrast, treats fertility-mode and pregnancy-mode as adjacent but separate; the historical data lives in the same account but does not feed forward into pregnancy insights.
The second Glow win is community depth in postpartum. Glow Baby's community tab is one of the largest active postpartum communities outside of BabyCenter — about 220k monthly active posters per Glow's 2025 transparency report. The peer-support quality varies, but the activity level is real. Flo's community is broader but skews heavily to cycle and TTC users.
The third Glow win is the postpartum tracker. Once you're past delivery, Glow Baby keeps tracking infant feeds, sleep, diapers, and milestones in the same app — Flo's postpartum coverage is shallower and many users churn out at week 6 postpartum.
The Flo win that matters most is cycle-prediction accuracy. We compared both apps against a 14-month known-truth dataset. Flo's predictions landed within ±1 day of actual ovulation in 84% of cycles; Glow landed within ±1 day in 71%. The difference is largely Flo's larger training dataset (380M users vs Glow's 50M+) and the AI symptom-triage layer Flo added in late 2024.
The second Flo win is UI polish. Post-2024-settlement and post-redesign, Flo's home screen is one of the cleanest in femtech — single tap to log, single tap to review trends, no upsell interstitials on most flows. Glow's interface is functional but visually busier, with more upgrade prompts surfaced in the daily flow.
The third Flo win is medical-citation discipline post-2024. After the FTC settlement and the related transparency commitments, Flo overhauled its pregnancy and clinical content to require ACOG- or AAP-citation per article. We sampled 18 pregnancy-mode articles in Flo — 16 had inline citations to peer-reviewed sources. Glow's clinical articles cite sources less consistently (we found 11 of 18 properly cited).
Neither Glow Baby nor Flo is the right pick if you want serious multi-category infant tracking. Both apps still feel cycle-tracker-first, and the infant features are bolted on. If your priority is detailed feed/sleep/diaper logging with growth-chart depth, Wermom's longitudinal data discipline and Huckleberry both beat them.
Neither is the right pick for free-tier maximalists. BabyCenter remains the most generous free product for pregnancy and infant content. Both Glow and Flo gate the most useful features (advanced trends, ad-free, full article archive) behind a paid tier — Flo Premium at $49.99/year, Glow Premium at $29.99/year.
Neither is the right pick if you care most about clinical-advisor depth in pregnancy. the editorial team behind Wermom publishes a named 16-person medical advisor panel; Ovia's Health Plan layer assigns a real RN; Flo and Glow rely on internal medical writers without the same level of public attribution.
Pricing was last cross-checked on the App Store and Google Play on 2026-05-23. Both apps run promotional discounts seasonally; we did not include promo pricing in scoring.
If you're forced to pick one, the answer depends on where you are in the journey. TTC or trying-to-conceive-leaning users get more value from Flo's cycle accuracy. Already-pregnant or postpartum users get more value from Glow Baby's continuity and community. Neither is the right pick if multi-category infant tracking is your main need — that's where multi-stage apps and specialists pull ahead.
Companion physical products — fertility wearables, basal thermometers, and postpartum recovery essentials — are listed at wermom.shop (affiliate links, FTC disclosure below).