Comparison
Flo 與 Stardust 2026：隱私、功能及價格比較
Our verdict
Flo was caught sharing data with Google and Meta. Stardust marketed privacy after Roe v. Wade but was found by Privacy International to send data to servers and use third-party de-identification. Neither delivers the privacy it promises. PinkyBloom needs no account, has no ads, and never sells your data.
Flo vs Stardust vs PinkyBloom
| Feature | Flo | Stardust | PinkyBloom |
|---|---|---|---|
| Price | ~$49.99/yr premium | Free | Free |
| Users | 440M+ | Millions (post-Dobbs surge) | Growing |
| Data storage | Cloud (Flo servers) | Cloud (de-identified via Rownd) | Stored on your phone |
| Privacy track record | Class action settled 2025; Flo paid $8M | Voluntary law enforcement cooperation | Never sold, no ads; partner sharing end-to-end encrypted |
| AI assistant | Cloud-based chatbot | Built-in AI assistant (Pinky) | |
| Voice logging | |||
| Mood forecasts | |||
| Astrology features | Astrology-themed insights | ||
| Account required | Email required | Google account required | No account needed |
| Safety Mode | Anonymous Mode (still cloud) | ||
| Doctor visit reports | |||
| Ads | Ads in free tier | No ads | No ads ever |
Overview
Flo 和 Stardust 在品牌定位上處於月經追蹤器光譜的兩端。Flo 是已建立的市場領導者——擁有 4.4 億用戶、全面的功能和企業健康平台的方式。Stardust 是後 Dobbs 隱私挑戰者——一個較小的應用程序，在最高法院的裁決後通過將自己宣傳為以隱私為首的月經追蹤器並提供占星主題的見解而激增下載量。
Flo 提供深度：AI 聊天機器人、70 多種症狀、社區論壇、懷孕模式和來自 120 多位醫療專家的內容。Stardust 提供差異化：融合占星的週期見解和與用戶突然關心其月經數據相呼應的隱私信息。
諷刺的是，這兩個應用程序都未能實現隱私。Stardust 的隱私聲明未能通過獨立調查。對於關心生殖數據隱私的用戶——尤其是在後 Dobbs 的環境中——這兩個應用程序都未提供架構保護。
Privacy comparison
The privacy comparison between Flo and Stardust is a case study in two different kinds of failure.
Flo's data sharing is documented in an FTC complaint and a federal class action. Menstrual data went to Google, Meta, and analytics firms. Flo paid $8M to settle in 2025, admitting nothing. A California jury found Meta liable for eavesdropping. Flo did the thing everyone fears a period tracker will do.
Stardust positioned itself as the antidote to Flo's failures. After the Dobbs decision, it marketed privacy and surged in downloads. But in June 2022, Vice/Motherboard discovered Stardust's privacy policy stated it would cooperate with law enforcement "whether or not legally required" — meaning voluntary handover of menstrual data to police. Stardust changed the wording only after press inquiry.
Then in May 2025, Privacy International revealed deeper issues: Stardust sends data to servers and relies on Rownd, a third-party de-identification service. A Google account is required, linking your menstrual data to Google's identity ecosystem. De-identification is a process, not a guarantee — academic research shows menstrual data can be re-identified with few data points.
PinkyBloom needs no account and never sells your data. Your cycle log is stored on your phone, with no third-party de-identification services. Safety Mode swaps neutral data into what she shares with a partner.
Features and intelligence
Flo's feature set dwarfs Stardust's. AI chatbot, 70+ symptoms, community forums, pregnancy mode, and thousands of articles. Flo is a comprehensive health platform.
Stardust's main differentiator is astrology-themed cycle insights — connecting your cycle to astrological concepts. The tracking itself is basic: cycle predictions and symptom logging. For users who enjoy the astrology angle, it's engaging. For users who want health intelligence, it's limited.
PinkyBloom provides genuine AI intelligence. Pinky, the built-in AI assistant, handles health conversations, voice logging captures symptoms naturally, mood forecasts predict emotional patterns, and doctor visit reports create professional summaries. It's the substance that both Flo's chatbot and Stardust's astrology insights point toward.
Pricing comparison
Flo charges ~$49.99/year for premium; its free tier has ads. Stardust is free with no ads.
Both apps store data in the cloud. Flo monetizes through subscriptions and (historically) advertising partnerships. Stardust's monetization model is less clear, but the Google account requirement and server-side data processing suggest data plays a role.
PinkyBloom is free. No ads, no Google account linkage. The total cost is $0.
There's a better option
Flo betrayed user trust with documented data sharing. Stardust promised privacy but relies on servers and third-party de-identification. PinkyBloom has no accounts to identify you, no ads, and never sells your data. Safety Mode replaces her shared status with neutral data, which neither app offers.
