How Mulsy works — one link, one room, everyone in sync.
Mulsy is a watch-party for YouTube videos. There are no accounts, no databases and no installs — rooms exist in memory while people are connected, and disappear when the last person leaves. Here's everything the app does.
Create a room
The landing page generates a random five-character room code for you (no ambiguous letters, so codes are easy to read out loud). Hit "Create a room" and you're the host — the attendees list marks you with a crown. If you ever leave, the crown passes to the next person in the room.
Share the code
Copy the room link and send it anywhere. Friends open it on any device and join with a click — or they type the code into the "Join" field. The attendee list fills up live, and everyone can set their own display name (saved in their browser). A live counter shows how many people are watching.
Play together
Paste any YouTube URL (watch, short, or youtu.be link) and it loads for everyone. When anyone plays, pauses, or seeks, the whole room follows — the server tracks the playhead so a late joiner lands exactly where everyone else is, not at zero.
Queue what's next
Anyone can add a video to the shared queue or remove one. Turn on "Auto-play next" and when the current video ends, the next one in the queue starts automatically for the whole room. Thumbnails come straight from YouTube — no API key needed.
Reconnect and recover
If the connection drops, Mulsy reconnects automatically and re-syncs to the room. Even if the server restarts, your player keeps its video and claims it back into the room — no frozen frames, no refresh required.