SyncUp syncs YouTube, Twitch and Netflix viewing between friends — no sign-up needed for basic features

The web service SyncUp lets several people watch videos and streams in sync from different locations. To get started, you just create a room and send friends a six-digit code or a link — no account registration is required for the basic features.

YouTube, Twitch, Kick, SoundCloud and YouTube Music work directly in the browser. SyncUp also claims support for more than a thousand sites with standard HTML5 players. If one participant pauses the video, seeks through it or resumes playback, the room’s state is automatically passed on to everyone else.

For YouTube, the developer claims synchronization to within roughly 200 ms. The video itself still loads directly from the source platform — SyncUp doesn’t compress or relay the stream, it only syncs the playback position.

Netflix and other streaming services require an extension

With DRM-protected platforms, the setup is different. Netflix, Disney+, Prime Video, Max, Hulu, Crunchyroll, Paramount+, Apple TV+ and Peacock work through the free SyncUp browser extension.

Each participant still needs their own active subscription to the relevant service. SyncUp doesn’t pass a movie or show from one user to the others — the extension simply keeps each participant’s own video player at the same moment.

That also creates a limitation for mobile devices. YouTube, Twitch, Kick and regular HTML5 video work through a mobile browser, while DRM services are currently intended for computers, since mobile browsers don’t support the required extension.

Rooms include voice chat and local file viewing

Beyond synchronization, SyncUp offers text and voice chat, a shared queue with voting, and support for SRT, VTT and ASS/SSA subtitles. Each viewer can adjust subtitle size and styling separately.

There’s also a more unusual feature: a local video file can be sent to other participants directly over P2P, without uploading it to the service’s servers first. The file stays on the owner’s device, and SyncUp syncs viewing between room participants.

A free room holds up to five people, and the built-in voice chat is limited to one hour per day. The Plus subscription raises the limit to 50 participants, removes the voice chat limit and adds permanent rooms, passwords and additional settings. At the time of publication, the subscription costs from $3.33 per month with annual billing, or $3.99 with monthly billing.

As a result, SyncUp sits between simple co-viewing services and dedicated watch party apps: for YouTube and Twitch, you just open the site, while major streaming platforms require only the extension and each viewer’s own subscription.