SynchCast is a software application designed for Windows laptops that enables users to stream system audio to multiple Bluetooth and wired devices simultaneously. Its primary function is to synchronize audio playback across various output devices, such as earbuds, speakers, headphones, HDMI monitors, and USB DACs, allowing multiple listeners to hear the same audio from a single laptop without sharing a single pair of earbuds. The application includes several notable features. It supports broadcasting to up to five devices, with hardware limitations determining the exact number. Users have independent control over volume and delay for each connected device, allowing for adjustments such as setting a speaker to full volume while keeping earbuds at a lower level. An adaptive drift correction mechanism, described internally as a PI-controlled resampler, compensates for clock drift between devices to maintain alignment during long listening sessions. The software also supports hot-plugging, meaning a new Bluetooth device paired mid-session appears automatically without requiring a restart. SynchCast uses a pure WASAPI loopback to capture audio, avoiding the need for kernel drivers, virtual audio cables, or administrative rights. The application can minimize to the system tray and continue broadcasting in the background. Typical use cases include shared audio experiences in close quarters. Couples can each use their own Bluetooth earbuds to watch a movie on a train or bus without sharing or exposing each other to ambient noise. Groups can watch a movie on a laptop during a hostel or dormitory movie night, with each person connecting their own headphones to avoid disturbing others. For parties, multiple Bluetooth speakers can be connected around a room to play synchronized music from one laptop. The workflow is straightforward: users download and run the installer, which requires no administrative rights or technical configuration. After launching, they select the devices to broadcast to, then press a start button to begin synchronized playback of system audio. Technical requirements are minimal. The application runs on Windows laptops and does not require driver installations, configuration files, or administrative access. It is activated on one machine and includes free updates for life. The software is offered as a one-time purchase with no subscription fees, and includes a 30-day full trial period.