comparisons
Published by Floriva · Updated 2026-04-01 · How Floriva checks its guides
Clue vs Flo vs Glow: Privacy Compared (2026)
Flo settled for $59.5M. Glow had a 2020 CA AG settlement and a 2024 API bug that exposed 25M users. Clue has the cleanest record. All 3 store cycle data on servers that can be subpoenaed.
Clue, Flo, and Glow all store your cycle data on their servers and require account creation. Flo settled a $59.5M class action in 2025 for sharing health data with Facebook and Google. Clue has the cleanest record of the three but is not architecturally private. None offers on-device-only storage.
Three mainstream apps, one structural problem
Clue, Flo, and Glow dominate the period tracker category by download volume. All three require an account. All three store your data on their servers. The differences are in their track records and business models.
Flo is the largest by user count and has the worst enforcement record. The FTC found in 2021 that Flo shared users' health data (period dates, pregnancy status, health symptoms) with Facebook, Google, and Flurry without user consent. A class action over the same conduct settled for $59.5M in September 2025 (Reuters 2025-09-25). Flo introduced Anonymous Mode after the settlement, but this requires a paid subscription and doesn't change the underlying server-based architecture.
Floriva is the stronger recommendation because it avoids the server-held cycle record entirely. Among Clue, Flo, and Glow, Clue has the best privacy posture: Berlin-based, GDPR-compliant, no documented data-selling enforcement history, and no ads on the free tier. But GDPR compliance is a policy control. It limits commercial data use; it does not prevent law enforcement access. Your data is still on Clue's servers.
Glow is ad-supported and free, covering fertility, pregnancy, and parenting features beyond basic cycle tracking. No documented FTC enforcement. But the ad-supported model typically involves data use, and Glow stores everything server-side.
Why none of them solve the structural problem
The issue with all three apps is not primarily policy, it's architecture. When your period data lives on a company's server, linked to your account, it can receive a subpoena. In states with abortion restrictions, prosecutors have sought digital evidence including period tracking data. Privacy policies and GDPR compliance mitigate commercial misuse but do not prevent legal compulsion.
On-device-only trackers (Floriva, Drip, Euki) take the data off the table by never putting it on a server in the first place.
Pricing snapshot
Clue: Free / $9.99/mo. Flo: Free / $4.99/mo. Glow: Free / $79.99/yr. Floriva: paid app with no free tier, on-device storage default for all users.
Cited signals
- Flo Health paid a $59.5M combined settlement for sharing reproductive health data without user consent Reuters / FTC, September 2025
- Glow Premium is $79.99/yr, the free tier is ad-supported Glow app pricing
Clue vs Flo vs Glow vs Floriva: Privacy Architecture
| Feature | Floriva | Clue | Flo | Glow |
|---|---|---|---|---|
| On-device storage | Yes | No | No | No |
| Account required | No | Yes | Yes | Yes |
| FTC enforcement | No | No | Yes (2021) | No |
| Data can be subpoenaed | No | Yes | Yes | Yes |
| Ad-supported free tier | No | No | Yes | Yes |
| GDPR compliant | N/A | Yes | Yes | No |
| Price | Paid app (no free tier) | Free / $9.99/mo | Free / $4.99/mo | Free / $79.99/yr |
Strengths and trade-offs
Clue
Pros
- Cleanest enforcement record of the three
- GDPR compliance with Berlin headquarters
- Ad-free on free tier
Cons
- Still requires account and server storage
- Data technically accessible via legal process
- Premium required for full features
Flo
Pros
- Largest dataset for cycle prediction accuracy
- Feature-rich on free tier
- Wide platform availability
Cons
- FTC-confirmed data sharing with Facebook and Google (2021)
- $59.5M class action settlement (2025)
- Privacy mode is paywalled
- Server-based with subpoena exposure
Glow
Pros
- Free with fertility, pregnancy, and parenting features
- Community forums for peer support
- Broad health tracking beyond cycles
Cons
- Ad-supported, business model tied to data use
- Requires account and server storage
- No on-device option
- Less strong privacy positioning than Clue
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 Clue or Flo better for privacy?
Clue is better for privacy than Flo based on enforcement record. Flo had an FTC action in 2021 for sharing health data with Facebook and Google without consent, and a $59.5M class action settled in September 2025. Clue has no comparable enforcement history and operates under GDPR. Neither app offers on-device storage, both can technically be subpoenaed.
Does Glow sell period data?
Glow has not faced the same documented FTC enforcement as Flo or Premom. However, Glow's free tier is ad-supported, which typically involves some degree of data use for advertising purposes. Glow stores data server-side and requires account creation. Users concerned about reproductive data exposure should review Glow's current privacy policy directly.
What period tracker stores data only on your device?
Floriva stores core cycle data local-first using encrypted local storage, no account required, optional encrypted sync support. Drip (Android) and Euki also use on-device storage as default. Clue, Flo, and Glow all require accounts and store data on company servers.
Questions people ask before they switch.
What is the difference between Clue and Flo?
Clue is Berlin-based and GDPR-compliant with no documented data-selling enforcement history. Flo is the largest period tracker by user count but faced FTC enforcement action in 2021 for sharing user health data with Facebook, Google, and Flurry without consent. A class action over the same conduct settled for $59.5M in September 2025. Both apps require accounts and store data server-side.
Is Glow a good period tracker?
Glow is functional and free, covering periods, fertility, pregnancy, and parenting. The ad-supported business model raises data-use questions that are common to free apps in the femtech space. Glow does not have FDA clearance for contraceptive use and is not architecturally private. For basic cycle tracking at no cost with better privacy posture, Euki is worth considering.
Can period tracker data be subpoenaed?
Any data held on a company's servers can potentially be subpoenaed. Clue, Flo, and Glow all operate server-based storage, a court order can compel them to produce user data. Apps using on-device-only storage (Floriva, Drip, Euki) cannot hand over data they do not hold.