Stemline for iOS. Last updated 11 September 2026.
Stemline collects nothing. There is no account, no analytics, no tracking, no advertising, and no third-party SDK of any kind. The app contains no networking code at all, so nothing you do in it can leave your device.
None. We do not collect, store, transmit, sell, or share any personal information or usage data. Because no data is gathered in the first place, there is nothing for us to disclose, retain, or hand to anyone else.
You choose audio files from your device using the standard iOS file picker. Stemline can only see the file you pick, and only because you picked it.
Separation runs entirely on your iPhone, using a machine learning model bundled inside the app. Your audio is never uploaded to any server, ours or anyone else's. The separated parts are written to Stemline's own storage on your device and stay there. Deleting a song in the app deletes its parts; deleting the app removes everything it created.
Stemline requests no privacy permissions. It does not ask for, and cannot access, your microphone, camera, location, contacts, photos, or health data.
The app makes no network requests. It works with the device in airplane mode, and there is no in-app browser, search, streaming, or download capability.
Stemline is not directed at children and collects no information from anyone, including children under 13.
Separation uses Demucs by Meta AI Research, converted to Core ML. The model runs locally as part of the app; it is software bundled in the binary, not a service, and it sends nothing to Meta or to us.
If this policy ever changes, the updated version will be posted on this page with a new date. Any change that affected what the app does with your data would also ship as an app update with its own release notes.
Questions about this policy: bramraysky232@gmail.com