Trying to watch a movie online with friends shouldn't feel like a chore. Yet, somehow, it often is. You either have to force everyone to create an account on a new platform, or you quickly realize that mainstream watch-party tools completely ignore self-hosted media servers like Emby, Jellyfin, or Plex.

I built KoalaSync to solve exactly this problem. Today, I am incredibly excited to announce KoalaSync 2.1—a massive update that makes perfectly synchronized movie nights more accessible, international, and smarter than ever before.

What is KoalaSync?

At its core, KoalaSync is a lightweight browser extension that synchronizes video playback across multiple devices in real-time. Whether you are binge-watching a series on Netflix, streaming from your private Emby server, or watching a standard HTML5 video on any website, KoalaSync keeps everyone perfectly in sync.

If you pause to grab a snack, the video pauses for your friends. If you skip the intro, everyone skips the intro. It just works.

Most importantly, it respects your privacy:

  • No Accounts Required: Just create a room, generate a link, and share it.
  • Zero Tracking: No analytics, no telemetry, no data collection.
  • RAM-Only Architecture: The official public relay server operates entirely in volatile RAM. No watch history or room data is ever saved to a database.

What’s New in Version 2.1?

While the core syncing engine has been rock-solid, version 2.1 brings some major quality-of-life improvements based on community feedback and rigorous testing.

🌍 Now Available in 13 Languages

A watch party tool is only as good as its accessibility. To make it easier to invite friends and family from all over the world, the KoalaSync UI is now fully localized into 13 different languages! Whether your friends speak Spanish, French, Japanese, or Polish, the extension will adapt to their native browser language out of the box.

🍿 Smart Binge-Watching (Auto-Sync)

Watching a TV show? You no longer need to manually recreate a room after every episode. When a new episode loads, KoalaSync detects the transition. It automatically places the room in a smart "waiting lobby," pausing the video for everyone until the last person’s stream has successfully buffered. No spoilers, and no one gets left behind.

🛡️ Enhanced Security

The backend has been upgraded with built-in rate-limiting and brute-force protection to prevent room-id spamming, ensuring your private watch parties stay private.

Join the Party

KoalaSync is 100% free and open-source under the MIT license. It's built as part of the broader KoalaStuff ecosystem, focusing on tools that prioritize user experience and data sovereignty.

Ready to host your next movie night?

Install the extension, grab your favorite snacks, and start syncing!

Last Update: June 05, 2026