Sync DJ plays audio in sync across devices. It doesn't have a server, doesn't collect data, and doesn't track you — and that shapes everything below.
time.apple.com (a single UDP packet containing no user data). Can be toggled off.UserDefaults). Never transmitted anywhere.Sync DJ keeps devices in time by agreeing on a shared start time, then having each device independently calculate its own playback position from the current time. There's no live connection between devices during playback — which also means there's nothing for Sync DJ to see, log, or relay.
To correct for differences between device clocks, Sync DJ can optionally query Apple's public NTP server (time.apple.com) to measure the offset between the device clock and network time. This is a single UDP packet containing only timestamp fields — no user data, device identifiers, or app information is included. The feature is on by default and can be toggled off in the Drop Time panel, in which case no network requests are made at all.
A handful of settings are saved to your device's local settings storage (iOS UserDefaults) so the app remembers your setup between launches:
Sync DJ also keeps a security-scoped bookmark — an iOS mechanism for remembering which file you picked — so it can reopen that file the next time you launch the app, without asking you to re-select it. This bookmark, like everything above, stays in your device's local storage. None of it is sent anywhere.
Sync DJ uses iOS's background audio capability so playback keeps running when your screen is locked or you switch apps — the same way any music app does. This permission is used solely for continuous playback and involves no data collection.
Sync DJ is not directed at children and collects no personal information from anyone, regardless of age.
If this policy ever changes, the effective date above will be updated. Given that Sync DJ collects nothing today, we don't expect much to change — but if the app's data practices ever do, this page will reflect it before that update ships.