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 re-hosting
It does not download, proxy, extract, or re-host video streams. You access the site directly.
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 (anonymous auth), 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.Quick Start Guide
Get up and running with SyncRoom in less than a minute.
1. Install Extension
Get SyncRoom from the Chrome Web Store. Pin it to your toolbar for easy access.
2. Create a Room
Open a YouTube or Bilibili video. Open the popup and click Start room on the Create tab.
3. Invite Guests
Click Copy invite link and send it. Guests will paste it in the Join tab to align to your page.
4. Connect Voice
Press Join Voice Chat to talk with friends. Voice chat persists across popup closes.
Frequently Asked Questions
Have questions about how SyncRoom functions? Here are some quick answers.
Does SyncRoom stream the video?
No. SyncRoom does not stream, proxy, or host any video content. It only synchronizes playback state (position, playing/paused, speed) and WebRTC voice signals. Everyone fetches their own 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.
Do all viewers need access to the video?
Yes. Because SyncRoom runs on the original page, each viewer must be able to load the video themselves (e.g., they must not be blocked by geo-restrictions, age gates, or paywalls).
What data does SyncRoom share?
SyncRoom only 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 browsing history.