comparisons
Published by Floriva · Updated 2026-04-01 · How Floriva checks its guides
Flo vs Stardust: Which Is Actually Private (2026)
Flo paid $59.5M for sharing reproductive data with Facebook. Stardust markets privacy but stores cycles server-side. Neither app is subpoena-proof.
Flo has a documented history of sharing user reproductive health data with Facebook and Google, settling for $59.5M in 2025. Stardust positions around astrology and privacy-forward messaging but stores data server-side behind policy controls. Neither offers on-device architecture.
Privacy as marketing vs privacy as architecture
Stardust launched with strong privacy-forward messaging. When Roe v. Wade was overturned, Stardust saw significant downloads from users looking for a safer alternative to Flo. Stardust positioned against Flo's data practices explicitly.
The positioning is better than Flo's. No documented FTC enforcement. No class action settlements for data selling. But Stardust still requires an account and stores data server-side. The privacy claims are real in the commercial sense. Stardust appears not to monetize your data the way Flo did. The limitation is that commercial privacy commitments and legal compulsion are different things.
Flo's track record
Flo is the most downloaded period tracker and has the worst documented data-sharing history in the category. The FTC found in 2021 that Flo shared users' reproductive health data with Facebook, Google, and Flurry despite explicit privacy promises. A $59.5M class action settlement followed in September 2025 (Reuters 2025-09-25).
Flo's Anonymous Mode, introduced after the settlement, is a paid feature. It reduces the data linkage within Flo's systems but does not change the fact that data exists on Flo's infrastructure.
What "policy-based privacy" actually means
Both Flo and Stardust offer policy-based privacy: they make commitments about what they will and won't do with your data. Policy controls can fail through corporate decisions, data breaches, or legal compulsion. A subpoena doesn't ask permission.
Architecture-based privacy works differently. If readable data stays off company servers, there is less for the company to produce. Floriva keeps core records on your device and encrypts optional sync so Floriva cannot read synced records. Euki and Drip are local-only options.
Cost
Flo Free is functional. Flo Premium is $4.99/mo. Stardust Free tier is available and Premium is $7.99/mo. Floriva is a paid app with no free tier, with on-device storage as the default for all users. No upsell required for privacy.
Cited signals
- Flo Health paid a $59.5M combined settlement for sharing reproductive health data without user consent Reuters / FTC, September 2025
Flo vs Stardust vs Floriva: Data Handling Comparison
| Feature | Floriva | Flo | Stardust |
|---|---|---|---|
| On-device storage | Yes | No | No |
| Account required | No | Yes | Yes |
| FTC enforcement history | No | Yes (2021) | No |
| Data can be subpoenaed | No | Yes | Yes |
| Privacy marketing emphasis | Architecture-based | Low | High |
| Astrology features | No | No | Yes |
| Price | Paid app (no free tier) | Free / $4.99/mo | Free / $7.99/mo |
Strengths and trade-offs
Floriva
Pros
- On-device storage, nothing on servers
- No account required
- Privacy enforced by architecture, not messaging
Cons
- Paid subscription required, no free tier
- No astrology features
- Smaller feature set at launch
Flo
Pros
- Most feature-rich free tier in the category
- Large dataset improves prediction accuracy
- Comprehensive health logging
Cons
- FTC-confirmed data sharing with Facebook and Google
- $59.5M class action settled 2025
- Privacy mode costs extra
- Cloud-based storage with subpoena exposure
Stardust
Pros
- Explicit anti-data-selling positioning
- Unique astrology angle for interested users
- No documented FTC enforcement history
Cons
- Privacy is still policy-based, account and server required
- Data technically accessible via legal process
- Smaller user base means less data for predictions
What the experts say
Apps like Flo shared users' most intimate data with companies like Facebook and Google. Users had every reason to expect that information would remain private.
Quick answers to the obvious questions.
Is Stardust a private period tracker?
Stardust markets itself with stronger privacy messaging than Flo and has not faced FTC enforcement actions. However, Stardust requires an account and stores data server-side. Privacy policies limit commercial data use but do not prevent law enforcement access via court order. Stardust's privacy posture is better than Flo's on record, but the architecture is similar.
What did Flo do with user data?
The FTC found that Flo shared users' reproductive health data, including period dates, pregnancy status, and health symptoms, with Facebook, Google, and Flurry despite promising confidentiality. The FTC took enforcement action against Flo in 2021. A combined class action settlement of $59.5M was reached in September 2025 (Reuters 2025-09-25). Flo launched Anonymous Mode after the enforcement action, but this feature requires a paid subscription.
How do Flo and Stardust compare on privacy after the $59.5M settlement?
Flo shared reproductive health data with Facebook and Google, confirmed by FTC enforcement in 2021 and a $59.5M class action settled in September 2025 (Reuters 2025-09-25). Stardust has no comparable enforcement history and positions against data selling. The gap in track record is real. The gap in architecture is not: both apps store data server-side, both require accounts, and both can receive subpoenas. Stardust's privacy is better in practice but identical in legal exposure.
Which period tracker has the best privacy?
Period trackers that keep readable records away from company databases offer the strongest architectural privacy. Floriva keeps core records on your device and optional sync is encrypted so Floriva cannot read synced records. Euki and Drip (Android) are local-only options. Among server-based trackers, Clue and Stardust have cleaner records than Flo.
Questions people ask before they switch.
Does Stardust period tracker sell data?
Stardust has positioned itself explicitly against data selling and has not faced the same enforcement history as Flo. Users should review Stardust's current privacy policy for specifics on data use. The key technical fact remains: Stardust stores data server-side, which means it is technically accessible to law enforcement regardless of the company's commercial data practices.
Is Flo still safe to use?
Flo is still operational and the most-downloaded period tracker. After the FTC enforcement action, Flo introduced Anonymous Mode. However, this mode requires a premium subscription ($4.99/mo) and the underlying architecture remains server-based. Whether Flo is 'safe' depends on what risk you're managing: if you're concerned about commercial data sharing, Anonymous Mode addresses some of that. If you're concerned about legal subpoenas in states with abortion restrictions, on-device storage is the only structural answer.
What is the difference between Flo Anonymous Mode and Floriva?
Flo Anonymous Mode severs the link between your health data and your email address within Flo's system, but Flo has confirmed the data still exists on their infrastructure. Floriva keeps core records on your device, and optional sync is encrypted so Floriva cannot read synced records. Floriva's data protection is architectural, not just account-level.