SyncLounge

SyncLounge is a tool to sync Plex content across multiple players in multiple locations. Watch movies and TV shows together with friends and family, no matter where they are.

This is a continuation of the original SyncLounge project, modernized with Vue 3, Vuetify 3, and Vite.

What's Different

This fork has been substantially reworked from the original:

• Vue 3 + Vuetify 3 + Vite — Migrated from Vue 2/Vuetify 2/Webpack
• Built-in web player only — External Plex client control has been removed (it no longer works reliably with modern Plex)
• Chromecast support — Cast content to Chromecast devices ($5 Google Cast developer registration required)
• Discord/social previews — Share links generate rich OpenGraph embeds with poster images and metadata
• MKV direct play — Properly handles MKV containers that Plex repackages as MP4
• Subtitle fixes — Fixed libjass subtitle rendering in Vite's ESM strict mode
• Mobile-friendly — Responsive layout improvements for small screens
• Library browsing — Sort, filter, and A-Z index for library content; lazy loading with skeleton placeholders
• Server management — Enable/disable servers with visibility toggles; all servers searchable by default

How It Works

SyncLounge keeps multiple viewing sessions in sync using a WebSocket server as a relay between clients. Users join a room, and the host controls playback — play, pause, seek, and content changes are synced to everyone in the room. If the host plays something new, SyncLounge searches each user's available Plex servers for a matching copy.

Features

• Synchronized playback across the internet
• Built-in web player optimized for sync accuracy
• Chromecast casting support
• Autoplay — automatically finds matching content across your Plex servers
• Library browsing with sorting, filtering, and A-Z quick navigation
• Search across all connected Plex servers
• Chat with room members
• Optional Plex user and server authorization allowlists
• Shareable invite links with rich social previews
• Configurable sync flexibility and sync method (clean seek / skip ahead)

Running

Docker

docker run -p 8088:8088 ghcr.io/chrisae9/synclounge:latest

Docker Compose

services:
  synclounge:
    image: ghcr.io/chrisae9/synclounge:latest
    ports:
      - 8088:8088
    restart: unless-stopped

Development builds are published separately as ghcr.io/chrisae9/synclounge:dev. Every development build also has an immutable dev-<commit SHA> tag. These images may be unstable and never replace latest.

Node.js

SKIP_BUILD=true npm ci
npm run build
node server.js

Listens on port 8088 by default. The documented deployment serves SyncLounge at the root of a hostname; path-prefix deployments require additional asset-base configuration and are not currently supported by the published image.

Configuration

Configuration can be set via environment variables matching the keys in config/defaults.js. Nested objects and arrays are passed as JSON strings:

AUTHENTICATION='{"mechanism":"plex","type":["server"],"authorized":["MACHINE_ID"]}'
SERVERS='[{"name":"My Server","location":"Mothership","url":"https://myserver.com"}]'

Only documented browser configuration is returned from /config.json; arbitrary keys in a configuration file remain server-side. TRUST_PROXY controls which reverse proxies may supply client addresses. It defaults to loopback, matching the Nginx example below. For a proxy on a private container network, prefer an explicit hop count or the proxy's exact CIDR. A named range such as uniquelocal is safe only when the application is directly reachable by that reverse proxy; other clients on the trusted network could otherwise spoof X-Forwarded-For and bypass per-IP limits. Do not use TRUST_PROXY=true. Set PUBLIC_ORIGIN to the externally reachable HTTP(S) origin (for example, https://synclounge.example.com) to enable absolute poster URLs in Open Graph previews. Incoming Host headers are never used to construct those URLs.

Reverse Proxy (Nginx)

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      '';
}

server {
    listen 443 ssl http2;
    server_name synclounge.example.com;

    location / {
        proxy_pass http://127.0.0.1:8088;
        proxy_http_version 1.1;
        proxy_socket_keepalive on;
        proxy_redirect off;

        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Host $server_name;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
    }
}

Development

SKIP_BUILD=true npm ci
npm run serve   # Vite dev server with HMR
npm run build   # Production build to dist/
npm test        # Run tests

Pull requests target dev; main is reserved for stable release promotions. See CONTRIBUTING.md for the complete verification and review contract.

Chromecast

Chromecast support requires a Google Cast developer registration ($5 one-time fee) and a published receiver app. The receiver app ID is configured in the SyncLounge settings.

Credits

Originally created by samcm, ttshivers, and contributors.

Continued by chrisae9.

License

MIT License. See LICENSE.

SyncLounge is in no way affiliated with Plex Inc.