SyncRoom
Watch and talk together from the original video page.
Start from a supported video page, share one invite, and keep play, pause, seek, speed, and voice in sync.
Works on YouTube, Bilibili, and supported pages with HTML5 video.
SyncRoom Ready Watch and talk together from the original page
Start from this video
Create a room to sync playback and open voice chat with friends.
How it works
SyncRoom layers on top of video sites. Zero video proxying or streaming needed.
Open the video
Everyone opens the video on the original site (YouTube or Bilibili). No re-hosting or downloads.
Start a room
The host creates a room from the browser extension popup. You instantly become the playback controller.
Share the invite
Send the invite link to your friends. They paste it under the Join tab to open the matching video.
Stay in sync
The host's play, pause, seek, and speed changes apply to everyone. Join voice chat to talk while watching.
Features
Everything you need for a synced watch party, packed into a lightweight browser extension.
Host Playback Sync
Authority is role-based. Only the host publishes states; followers apply changes automatically, using nudge rates for small drifts to keep audio smooth.
Built-in Voice Chat
Full-mesh WebRTC P2P voice chat running in a persistent offscreen document. Close the popup, reload pages - the voice line stays active.
Original-Page Watching
No iframe overlays, no embedded sites. You remain on the original video page, keeping all native quality, recommendations, subtitles, and comments.
Mismatch Warning
Detects if a guest opens a different video key than the host. Keeps everyone on the same page by warning when video identifiers do not match.
Recent Rooms List
Local history panel stores the rooms you recently visited. Rejoin a room or clean up old room connections with one click.
Platform Respect
SyncRoom acts only as a sync controller. It respects copyrights, does not download streams, and does not bypass paywalls or site restrictions.
Privacy by design
SyncRoom is built for watching together without taking over the video.
No stream handling
SyncRoom never touches the media stream itself; each browser connects directly to the original platform.
No history uploading
It does not upload your browsing history. Only active room context is shared.
Minimal data sharing
It only shares the active room's video identity, playback state, and voice connection signals to keep you in sync.
Original pages only
Each person watches from the original page they can already open in their browser.
Our Privacy Commitment
SyncRoom operates as a client-side layer. Connections are fully anonymous, and WebRTC signals run temporarily via Supabase Realtime without writing data back to databases. We do not track, identify, or target users.
Read the full Privacy Policy to see our details.Frequently Asked Questions
Short pointers for the most common setup and privacy questions.
Which sites does SyncRoom support?
SyncRoom is designed for original video pages. It supports YouTube, Bilibili, and supported pages where the extension can detect a standard HTML5 video element. Some sites may not work because they use custom players, restricted pages, DRM, or browser extension limitations.
Does SyncRoom stream, upload, or proxy videos?
No. SyncRoom does not stream, download, proxy, extract, or re-host any video content. It only synchronizes playback state (position, playing/paused, speed) and WebRTC voice signals. Everyone fetches their own video stream directly from the platform.
Does everyone need the extension?
Yes. Because SyncRoom runs locally inside your browser, everyone who wants to participate in the watch party and voice chat needs to install the SyncRoom browser extension.
Does everyone need access to the original video?
Yes. Because SyncRoom runs on the original page, each participant must be able to load the video themselves. If someone is blocked by region restrictions, an age gate, or a paywall, they will not be able to watch along even with SyncRoom installed.
Why does the page say video mismatch?
SyncRoom detects a stable video identity (for example, the YouTube video ID or Bilibili BV/episode identifier) for the host and for each guest. A mismatch warning appears when a guest's video identity does not match the host's, which usually means a different video, episode, part, or regional version was opened.
Why is voice chat not connecting?
Voice chat uses peer-to-peer WebRTC connections. If it does not connect, check that your browser has granted SyncRoom microphone permission and that your network or firewall allows WebRTC/peer connections.
What microphone data is used?
Your microphone audio is only captured after you explicitly click Join Voice Chat, and it is sent directly to other room members over a peer-to-peer WebRTC connection. SyncRoom does not record, store, or upload voice chat audio.
What room data is shared?
SyncRoom shares the active room ID, your anonymous member ID, the video URL/key (for mismatch detection), playback state (playing/paused, time, speed), and temporary WebRTC signaling for voice chat. It never uploads your browsing history.
Does SyncRoom collect browsing history?
No. SyncRoom does not collect or upload your general browsing history. It only reads the video page you actively open the extension on, and only shares the specific room context described above.
Can followers control playback?
No. Room authority is role-based: only the host (owner/controller) can publish play, pause, seek, and speed changes. Followers apply the host's state automatically and cannot write playback changes back to the room.
Does it work on mobile?
SyncRoom is a desktop browser extension built for Chrome and other Chromium-based desktop browsers. It does not currently support mobile browsers, since most mobile browsers do not support installing extensions.
Does it work in Edge?
SyncRoom is built on Manifest V3 and is compatible with Edge and other Chromium-based browsers using the same Chrome Web Store listing, though Chrome is the primary supported browser.
What should I do if the popup cannot detect a video?
Reload the video page after installing or updating SyncRoom, and make sure you are on an actual video playback page rather than a channel, search, or homepage. If the site uses a custom or DRM-protected player, SyncRoom may not be able to detect it.