Flo vs Clue: Which Period Tracker Is Actually Private?

Flo vs Clue vs Floriva: Privacy Architecture Comparison
Feature	Flo	Clue	Floriva
On-device storage	No	No	Yes
Account required	Yes	Yes	No
Data can be subpoenaed	Yes	Yes	No — nothing on servers
FTC enforcement history	Yes (2021)	No	No
GDPR compliant	Yes	Yes	N/A — no server data
Anonymous Mode	Paid only	No	Default
Price	Free / $4.99/mo	Free / $9.99/mo	$2.99/mo

The core difference: policy vs architecture

Flo and Clue both claim to protect your privacy. The difference is how that protection works — and what happens when a court disagrees with their privacy policy.

Flo’s record: In 2021, the FTC found that Flo shared user health data — including period dates and pregnancy information — with Facebook and Google despite promising not to. A class action lawsuit over the same conduct settled for $59.5M in September 2025 (Reuters 2025-09-25). Flo responded by introducing Anonymous Mode, but this feature requires a paid subscription and the underlying architecture remains cloud-based.

Clue’s position: Clue has not faced the same enforcement actions as Flo. Being GDPR-compliant and Berlin-based means commercial data sharing is more tightly regulated. But GDPR compliance does not equal subpoena-proof. Your data still lives on Clue’s servers. A valid court order can compel Clue to produce it.

What server-side storage actually means

Both Flo and Clue need an account to function. Creating an account means your cycle data is linked to your identity on their servers. This is fine until it isn’t — a divorce proceeding, an insurance dispute, a criminal investigation in a state with abortion restrictions.

On-device-only trackers like Floriva take a different approach: nothing leaves your phone except via opt-in encrypted sync. There is no company server holding your data. There is nothing to subpoena.

Pricing comparison

Flo’s free tier is functional but shows ads and limits predictions. Premium is $4.99/mo or $39.99/yr. Anonymous Mode requires premium. Clue’s free tier is ad-free with solid core tracking. Plus is $9.99/mo or $59.99/yr for cycle health reports and birth control tracking. Floriva is $2.99/mo with no tiered privacy — on-device storage is the default for all users.

Which to pick

If you’re choosing between Flo and Clue purely on privacy, Clue is the better choice: no documented data-selling history, GDPR compliance, and a cleaner enforcement record. If you want structural protection — data that cannot be handed to a third party because it never left your device — neither Flo nor Clue provides that. Floriva does.

Neither feels private enough?

Floriva stores everything on your device. No data sold, no account required.

Verdict

Both Flo and Clue store your reproductive health data on their servers. Flo has a worse track record — an FTC enforcement action and a $59.5M class action — but Clue's GDPR compliance doesn't prevent a subpoena. If you're in a state where reproductive data carries legal risk, neither app offers structural protection.

PROS & CONS

Flo

Pros

Strong cycle prediction from large dataset
Feature-rich symptom tracking
Wide platform availability

Cons

FTC-confirmed data sharing with Facebook and Google (2021)
$59.5M class action settlement (2025)
Server-based — subpoena risk exists
Privacy requires paying for Anonymous Mode

PROS & CONS

Clue

Pros

GDPR compliance, Berlin-based
No ads on free tier
Research-backed predictions

Cons

Account and server storage required
GDPR is a policy control, not a technical one
Data accessible via legal process to German or US authorities

PROS & CONS

Floriva

Pros

On-device storage — no server to subpoena
No account required
Privacy by architecture, not by policy
$2.99/mo flat

Cons

Smaller feature set at launch
Cross-device sync uses end-to-end encryption (opt-in)

Does Clue sell your period data?

Clue does not have a documented history of selling user data the way Flo does. Clue is GDPR-compliant and Berlin-based. However, Clue still requires an account and stores data server-side, which means it can be accessed via court order or government request. GDPR compliance limits commercial data sharing but does not prevent law enforcement access.

Is Flo or Clue safer for privacy?

Clue has a cleaner privacy track record than Flo. Flo faced FTC enforcement action in 2021 for sharing sensitive health data with Facebook and Google without user consent, then faced a $59.5M class action settled in September 2025. Clue's GDPR compliance provides stronger data protection in the EU context. That said, both apps require server-side storage, so neither provides architecture-level protection against subpoenas.

Which period tracker keeps data only on your phone?

Floriva stores all cycle data exclusively on your device using encrypted local storage. No account is required and no data is transmitted to company servers, which means there is nothing to subpoena. Drip (Android) and Euki also use on-device storage as their default architecture.

Frequently Asked Questions

What did Flo do wrong with user data?

The FTC found that Flo shared users' reproductive health information — including period dates, pregnancy status, and health symptoms — with Facebook, Google, and Flurry despite promising to keep this data private. The FTC took enforcement action against Flo in 2021. A class action lawsuit resulting from the same conduct settled for $59.5M in September 2025 (Reuters 2025-09-25).

Is Clue compliant with GDPR?

Yes. Clue is headquartered in Berlin and operates under GDPR. This limits how Clue can commercially use or share your data within the EU framework. However, GDPR does not prevent data from being handed over pursuant to a valid court order or law enforcement request, particularly for US-based legal proceedings.

Can period tracker data be used as evidence in court?

In states with abortion restrictions, prosecutors have sought digital evidence including period tracker data. Apps that store data on company servers can receive subpoenas. Apps that store data only on your device cannot hand over what they do not have. This is the structural difference between server-based trackers (Flo, Clue) and on-device trackers (Floriva, Drip, Euki).

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