SyncTube turns any browser into a shared movie room where one link opens a synchronized player and live chat for the whole group. Paste a YouTube, Twitch, Vimeo, or PeerTube URL, or a direct mp4 or m3u8 link, and the room watches the same frame at the same moment. A leader takes global control of play, pause, seeking, and playback rate, and smaller groups can open pausing or resuming to everyone. Local files start playing for the room while they upload, and external subtitle files plus separate audio tracks cover voiceovers and fan translations. Chat doubles as a remote control: timed commands jump the whole room forward or back, skip a sponsored segment, boost quiet audio, or return to the moment before an accidental rewind. Playlists accept ranged link patterns for episode batches, viewers vote to skip, and keyboard shortcuts drive fullscreen, refresh, and sync toggles without leaving the player. Operators can cache supported site videos on the server, restyle every front-end file, and extend subtitle rendering or quality switching through plugins. Admins moderate with bans and kicks from chat, and the whole service runs from one small server that fits a private friends-only room or a public community channel. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.