KoalaSync | Sync Netflix, YouTube & Any Video with Friends

Perfect for Any Occasion

Whether near or far, KoalaSync brings people together around their favorite videos.

Two cute koalas sitting together and sharing a bucket of popcorn

Movie Night with Friends

Sync your movies in real time and talk via Discord, Zoom, or your favorite voice call application. It feels just like sitting in the same room.

A koala professor presenting on a screen to two remote student koalas

Remote Learning

Analyze online tutorials, lectures, or developer training streams together with classmates or colleagues. Pause and discuss complex steps in perfect harmony.

A cute koala couple watching together remotely; one is sitting at a PC and the other is in bed with a laptop, with flying hearts between them

Long-Distance Relationships

Bridge the distance and enjoy date nights. Experience every plot twist, laugh at the same jokes, and share emotional moments at the exact same millisecond.

A cute koala with a question mark above its head wondering why to choose KoalaSync

Why KoalaSync?

Built for reliable sync, privacy-first design, and easy setup.

Full Control / Instant Sync

One pauses, everyone pauses. One seeks, everyone follows. Our two-phase sync protocol coordinates playback in real time across all participants.

Endless Binge-Watching

Autoplay in sync. KoalaSync automatically detects episode transitions and holds playback until all peers have successfully loaded the next video.

Zero Accounts / Pure Privacy

No registration, no tracking, no persistency footprints. The server runs entirely in ephemeral RAM and purges your room when you leave.

                        STATE: VOLATILE
                        RAM-ONLY
                    

Universal HTML5 Support

Works on YouTube, Twitch, Netflix, Jellyfin, Emby, and almost any standard webpage containing a HTML5 video element. Also compatible with custom self-hosted setups. No video data is ever sent to our servers — only synchronization metadata.

Instant Invites / 1-Click Join

No IP addresses or passwords to exchange. Share a generated invite link with your friends to let them join your room automatically with a single click.

Self-Hostable & Docker-Ready

Our official servers are free and fast, but you can take full ownership if you want to. Launch your own private relay server in seconds via Docker.

Open Source (MIT License)

The entire codebase is publicly auditable on GitHub. No black boxes, no proprietary blobs — 100% transparency from the relay server to the browser extension.

Volume Leveling / Audio Compressor

No more riding the volume knob. Built-in audio compressor boosts quiet dialogue and tames loud explosions. Works on Netflix, Prime Video, Disney+, YouTube, and any HTML5 video. Completely local — no audio data leaves your computer.

KoalaSync vs. Teleparty

See why open source, ad-free and privacy-first is the superior way to watch together.

Feature	KoalaSync	Teleparty
Cost / Paywalls Premium subscriptions, hidden fees or locked features.	✔ 100% Free	✘ Paid Tiers / Premium Locks ^[1]
License / Code Auditable Whether the source code is open and freely auditable.	✔ Open Source (MIT)	✘ Proprietary ^[2]
Self-Hosting Ability to deploy your own private relay server.	✔ Yes (Docker-ready)	✘ No ^[2]
Privacy & Tracking Registration requirements, tracking cookies and analytics.	✔ Zero-Persistence (RAM-only)	✘ Google Analytics & Cookies ^[2]
Site Compatibility Supported websites and player compatibility.	✔ Almost any HTML5 Video^[3]	✘ Supported sites only ^[1]
Localization / Translation Available interface languages and translation support.	✔ 15 Languages (and growing)	✘ English only
Audio Compressor / Volume Leveling Built-in audio normalization to balance quiet dialogue and loud effects	✔ Yes (4 presets, dry/wet control)	✘ No

Comparison state: May 2026.

^[1] Official Teleparty Premium pricing and supported networks details: teleparty.com/premium

^[2] Teleparty privacy policies and tracking data collection: teleparty.com/privacy

^[3] Works on websites that allow script injections into standard HTML5 video tags. Websites with highly strict Content Security Policies (CSP), DRM copy protection, or heavily obfuscated player wrappers (like complex shadow DOMs) might restrict automated control or injection.

Getting Started

Install Extension

Add KoalaSync to your browser from the Chrome Web Store, Firefox Add-ons, or download the latest developer ZIP from GitHub.

https://sync.koalastuff.net

KoalaSync

Privacy-first video synchronizer

Download for Chrome

Download for Firefox

Create a Room

Open the extension popup and click '+ Create New Room'. KoalaSync automatically generates a secure Room ID and Password, joins it, and copies the invite link to your clipboard.

Share & Sync

Send the invite link to your friends. Once they join, select your video tab and enjoy synchronized playback.

🐨 KoalaPC PLAYING

▶

⏸

42:15

IN SYNC

💻 LaptopKoala PLAYING

▶

⏸

42:15

For Self-Hosters

Don't trust our server? Maintain full data sovereignty. Deploy your own private relay server in minutes.

A cute koala sitting at a laptop deploying a Docker container for self-hosting

services:
  koala-sync:
    image: ghcr.io/shik3i/koalasync:latest
    container_name: KoalaSync
    restart: always
    # Access internally by proxying to container port 3000
    environment:
      - TZ=Europe/Berlin
      - PORT=3000
      - MIN_VERSION=1.0.0
      - MAX_ROOMS=100
      - MAX_PEERS_PER_ROOM=50
    pids_limit: 2048

View all image tags on GitHub Packages →

sync.koalastuff.net {
    root * /var/www/koalasync/website/www
    encode zstd gzip
    
    # Clean URLs support (no .html required)
    try_files {path} {path}.html {path}/
    file_server
}

syncserver.koalastuff.net {
    reverse_proxy localhost:3000
}

(security_headers) {
    header {
        # Enable HTTP Strict Transport Security (HSTS)
        Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
        # Prevent clickjacking attacks (Sameorigin)
        X-Frame-Options "SAMEORIGIN"
        # Prevent MIME-sniffing
        X-Content-Type-Options "nosniff"
        # Enable browser XSS protection
        X-XSS-Protection "1; mode=block"
        # Control referrer information
        Referrer-Policy "strict-origin-when-cross-origin"
        # Hide Caddy server stamp signature
        -Server
    }
}

sync.koalastuff.net {
    encode zstd gzip
    root * /var/www/koalasync/website/www

    # Clean URLs: Resolves paths without .html in the URL
    try_files {path} {path}.html {path}/
    file_server

    # Static Caching for high performance
    @static {
        file
        path *.ico *.css *.js *.png *.svg *.webp *.avif
    }
    header @static Cache-Control "public, max-age=31536000, must-revalidate"

    # Hardened Security & Permission Policies
    import security_headers
    header {
        Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; connect-src 'self'; img-src 'self' data:; object-src 'none'; frame-ancestors 'none'; base-uri 'none'; form-action 'none';"
        Permissions-Policy "camera=(), microphone=(), geolocation=(), payment=(), usb=()"
    }
}

syncserver.koalastuff.net {
    import security_headers
    encode zstd gzip
    reverse_proxy KoalaSync:3000
}

Frequently Asked Questions

Everything you need to know about watching videos together in perfect sync.

Can I watch Netflix, Emby or Jellyfin together in sync with friends?

Yes! KoalaSync works on Netflix, YouTube, Twitch and any website with an HTML5 video player — including Emby, Jellyfin and self-hosted media servers. Install the extension, create a room, share the invite link, and everyone watches in perfect sync.

Does KoalaSync stream the video to my friends?

No. KoalaSync does not stream, host, share, or bypass access to video content. Everyone watches the video locally in their own browser and needs their own access to the website or streaming service, such as their own Netflix account. KoalaSync only synchronizes playback actions like play, pause, and seeking.

Is KoalaSync a free alternative to Teleparty?

100% free and open source under the MIT License. No premium tiers, no locked features, no ads — everything is included. Unlike Teleparty, KoalaSync's relay server is RAM-only with zero data collection or user accounts required.

Does KoalaSync work with Emby, Jellyfin and self-hosted media servers?

Yes. KoalaSync detects any standard HTML5 video element, which means it works perfectly with Emby, Jellyfin, Plex, and any custom self-hosted streaming setup. You can also self-host the KoalaSync relay server via Docker for complete data sovereignty.

Which browsers and platforms support KoalaSync?

Google Chrome, Mozilla Firefox, Microsoft Edge, Opera, Brave, and all Chromium-based browsers. Install it directly from the Chrome Web Store or Firefox Add-ons — no manual configuration needed.

Do all my friends need the extension installed?

Yes, each participant needs KoalaSync installed — but there's no sign-up or account creation. Simply click the invitation link, install the extension if you haven't already, and you'll join the room automatically in seconds.

Is my data safe? What if I don't trust the official server?

Completely safe. KoalaSync's relay server is RAM-only — all session data is permanently deleted the moment you leave the room. No database, no logging, no analytics, no accounts. And if you prefer full control: you can self-host your own private relay server via Docker in minutes. The entire codebase is open source and auditable on GitHub.

Can I fix quiet dialogue and loud explosions when watching videos in the browser?

Yes. KoalaSync 2.2.0 includes a built-in audio compressor that reduces the gap between quiet and loud parts of your video. It runs locally via the Web Audio API — no audio data ever leaves your computer. Open the popup, create a room, go to Settings → Audio Processing, toggle the compressor on, and pick a preset. Works on Netflix, Prime Video, Disney+, YouTube, and any HTML5 video site.

Watch Together.Sync Perfectly.