Stack iPhones. Hit play. The party gets loud. Up to eight phones sync to within 10 ms — no Bluetooth speaker, no internet, no accounts.
If you have a few friends and a few phones, you have a sound system. Beach trips, kitchen sessions, road trips, dorm hangouts — LoudParty fills the room.
Up to eight iPhones playing the same track at the same instant. Stack them. Spread them around the room.
Engineered for the human ear. Drift correction every 100 ms keeps audible offset below the threshold of hearing.
Peer-to-peer over Wi-Fi and Bluetooth — whichever radio is on. No router, no carrier, no accounts. Beach to basement, it just works.
Bring your own local audio files — MP3, FLAC, AAC, WAV. No streaming services, no DRM, no "track unavailable in your region".
Bundled Winamp-style visualizers run in lockstep on every listener. Spectrum bars, oscilloscope, plasma blobs — in sync with the audio, on every screen in the room.
Skip, pause, and switch tracks from the Lock Screen, Control Center, or AirPods double-tap. The host stays in your pocket.
Open LoudParty on one iPhone. Pick a track from your local library — MP3, FLAC, AAC, WAV. That phone is now the room's source of truth.
Friends open the app and tap your host card. Their phone wakes up as a listener over the local link — no pairing, no codes.
Hit play on the host. Every phone fires the same sample, at the same instant. The room becomes one big speaker.
Try every feature with three phones. Unlock the full eight when you're ready.
Every listener pings the host with an NTP-style ping/pong round and locks to the host's audio clock. Playback is sample-accurate: each phone schedules buffers against the iOS audio engine, then refines its offset every 100 ms. End-to-end audible drift stays under 10 ms — below what the human ear can resolve.
LoudParty is free for three phones. Unlock the full eight with Pro — $9.99 / year, cancel anytime.
Requires iOS 17.0 or later · iPhone & iPad