Last updated: July 2026.
Hairline is built to be private by default. It does not collect, transmit, or store your personal information on any server. There is no account and no sign-up.
Progress photos are taken or chosen with your permission and are processed and stored only on your device. They are never uploaded to us or to anyone else. The camera and photo-library permissions are used solely to add photos to your on-device timeline.
Your Hairline Check answers, your estimated stage, and your routine are stored only on your device. If you delete the app, this data is removed with it.
No analytics, no advertising, and no third-party trackers. We run no servers that receive your photos, your Check answers, or your routine.
The optional one-time unlock is handled by Apple on the App Store and by Google on Google Play. We never see or store your payment details.
To know whether you have unlocked Full Access, we use RevenueCat as our purchase-management provider. When you open the app it receives an anonymous identifier generated for your install, plus your purchase receipt if you buy. It does not receive your photos, your Check answers, or your routine, and it is not used for advertising. RevenueCat acts as our service provider and does not sell your data.
Hairline is intended for adults and is not directed to children.
Everything Hairline stores lives on your device, so deleting the app removes it. For the purchase records held by our provider, see Delete your data.
Questions about privacy: trendtweekers00@gmail.com.
Hairline is a tracking tool, not medical advice or a diagnosis.