VTuber's low-latency session app SyncueSong enters open beta

A VTuber developer released the Windows online singing and session app SyncueSong as an open beta on October 23, 2026, according to AV Watch. The app is free to use until its official release.

SyncueSong sends audio directly between peers over P2P rather than routing it through a server, and it supports ASIO drivers. Connections between IPv6 lines in the Tokyo area have shown round-trip times of about 10ms in some cases.

The app processes monitor audio and streaming or recording audio with separate buffers. Monitor output uses a small buffer to prioritize low latency, while the stream and recording output uses a buffer of about 100ms. Audio is sent as uncompressed PCM, with 48kHz/16bit as the default and 44.1kHz also selectable.

A SYNC function calculates the delay for each route in the mesh connection and automatically aligns the timing of each member's audio on the streaming and recording side. A monitor screen called SyncMon displays waveforms, buffer amounts and network routes. The streaming and recording output must be set to a device different from the monitor output, such as a virtual audio driver for OBS.

Closed beta ran since May

The developer has worked as a VTuber for nine years and belongs to a VR idol unit, and began developing SyncueSong around January 2025. A closed beta on a dedicated Discord server started in May 2026 and currently has about 100 testers, per AV Watch. During that phase the app was used in a live event connecting VRChat performers with a live house venue in Shinjuku, an event in which 13 participants took turns duetting, and an improvised voice drama.