comparisons

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.

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. That context matters: 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 post settlement, is a paid feature. It reduces the data linkage within Flo's systems but does not change the fact that