Sync DJ

Sync DJ turns a group of phones into one synchronized sound system, without streaming or Bluetooth. Load the same DJ mix on each device, agree on a drop time, and hit play — every phone locks to the same position in the track. Great for distributed dance parties, bike raves, silent discos, art installations, or multi-room home audio.

How it works

1. Everyone picks the same audio file from Files or iCloud
2. Set a shared drop time
3. Tap play — the app counts down to the drop, or jumps to exactly the right position
4. If you pause or lose connection, tap again to rejoin mid-mix

Internet time sync Sync DJ uses network time (NTP) to correct for differences between device clocks, so the drop lands at the same real-world instant on every phone — even if someone's clock is off by a few seconds.

Live spectrum analyzer A real-time frequency visualizer reacts to the music as it plays, with multiple colour themes to match the vibe.

Built for long mixes Hour-long sets, multi-hour mixes, all-day playlists — the playback engine handles it. Background audio keeps the music going when the screen locks.

No accounts. No streaming. No internet required after sync. Your audio files stay on your device. Sync DJ doesn't stream, upload, or share anything. The only network call is a single time-check to align clocks.

Features • Synchronized playback across unlimited devices • NTP clock correction for frame-accurate drops • Share drop times via syncdj:// deep links • Live spectrum analyzer with swappable colour themes • Background playback with lock screen controls • Automatically resumes after interruption without losing sync • Supports MP3, AAC, WAV, and AIFF • Works with Files, iCloud Drive, and any file provider • Countdown timer with live preview • No sign-up, no subscription, no ads