SyncTube

SyncTube is a lightweight web application that synchronizes video playback across connected users and provides an integrated chat and playlist interface. The project source is implemented using Haxe and runs on a Node.js runtime, with optional Docker deployment for convenience. (github.com)

Key Features

• Leader-controlled global playback (play/pause/seek/playback-rate) for coordinated viewing.
• Support for YouTube (videos, shorts, streams, playlists), Streamable, VK, PeerTube, raw mp4 and m3u8 playlists; iframes are supported (without sync).
• Local video upload support allowing playback to start before upload completes.
• External subtitle formats (vtt/srt/ass) and external audio/voiceover track support.
• Chat with built-in commands (time rewinds, flashback, volume, admin controls such as ban/kick/dump/crash) and hotkeys for quick control.
• Mobile-friendly compact view and Android page-fullscreen behavior.
• Plugin architecture (example plugins: octosubs, qswitcher) and ability to override front-end files via a user/res folder.
• Optional server-side YouTube cache feature (requires an optional ytdlp helper and ffmpeg to build cached mp4s).
• Docker and docker-compose files included for containerized deployment. (github.com)

Use Cases

• Friends or small groups who want to watch YouTube videos or direct media links in perfect sync while chatting.
• Remote watch parties, study groups, or media review sessions where a single leader controls playback and timing.
• Lightweight testing or demonstration of synchronized playback, subtitle and audio-track handling in a web environment.

Limitations and Considerations

• Authentication is minimal: users sign in with a nickname by default (no built-in persistent account system or full user management out of the box).
• Server-side YouTube caching requires optional external components (a ytdlp helper package and ffmpeg) and additional storage configuration.
• The repository shows no formal packaged releases; deployment is primarily via source build or provided Docker configuration. (github.com)

SyncTube is a focused, practical implementation for synchronized viewing and chat tailored to small groups and self-deployment. It emphasizes simplicity, extensibility and multiple deployment methods (direct Node.js or Docker), making it suitable for private watch parties and experimentation.