People ask this constantly and usually get a vague answer, so here is the direct one: a sync extension needs a computer on both sides. Not because anybody decided to skip mobile, but because phone browsers don't run extensions at all.
That is worth explaining properly, because it also tells you what does work.
Why extensions don't run on phones
An extension that syncs video has to do two things: run a small script inside the page you are watching, and keep a panel open beside it. Mobile browsers allow neither.
On Android, Chrome has never shipped extension support. There is no setting hidden somewhere, no developer mode — the API simply isn't in the mobile build. A couple of other Android browsers do support extensions, but ours needs Manifest V3 with the side panel, which those builds don't provide.
On iOS, every browser is required to use Apple's web engine, and extensions there are a separate system built around Safari — a different format, a different review, a different set of capabilities. A Chrome extension cannot be installed on an iPhone in any form.
So this is not a gap that a future release quietly closes. It is a platform boundary, and any watch-party tool that works by hooking the page's own player runs into exactly the same wall.
What actually works on a phone
Three options, in the order most people should try them.
1. The streaming service's own group watch, if it has one. This is the only approach that is genuinely built for phones, because it lives inside the service's own app. Availability changes and comes with conditions — everyone needs their own subscription, sometimes the same country — so check that service's help pages. When it exists, it beats every external tool on mobile.
2. Screen sharing from someone else's computer. Your friend shares their screen over Discord, Zoom or a video call, and you watch on your phone. It works, and for a one-off it is perfectly reasonable — but be clear about the cost: you are watching a re-encoded copy of their browser window, commonly capped around 720p on free tiers, and one machine carries the whole evening. The full comparison is here. On protected services it often produces a black rectangle for you, which is exactly what DRM is designed to do.
3. Watch on a computer and keep the phone for the call. This is what most people settle on, and it is better than it sounds.
The setup most people end up with
Video on the laptop, voice on the phone. It splits the two jobs across the two devices that are each good at one of them.
Open the video on a computer on both sides and let the extension keep the two playheads aligned — under 250 milliseconds, with one side pausing while the other buffers. Keep the phone in your hand for the call, which is where a phone actually shines: it has a decent microphone, you can move around with it, and it doesn't steal anything from the video.
We don't offer voice chat at any price, so you would be running the call separately regardless. The two don't interfere.
- Both people install the extension on a computer — download here. Chrome 116 or newer; Edge, Brave and Opera are expected to work but are unverified. Firefox and Safari are not supported.
- One of you opens the video and creates a room. You get an 8-character code, something like
k7mq2xw4. - The other person joins and opens the same video.
- Press the purple sync button. Both sides count down from three and start together.
- Call each other on your phones and leave it running.
What about a tablet?
The same rule applies and for the same reason: an iPad runs iOS browsers, so no Chrome extensions. An Android tablet runs the same Chrome build as an Android phone. Tablet size doesn't change what the browser supports.
A Chromebook, on the other hand, runs desktop Chrome and works normally.
One combination that doesn't work
One person on a computer, the other on a phone. The computer side would sync happily with nothing to sync against; the phone side would be pressing play by hand and drifting away within minutes, for all the usual reasons — ad breaks land per viewer and buffering is per connection.
If one of you only has a phone tonight, screen sharing is the option that actually holds you together, with the quality trade-off above.
Before you start
Rooms hold up to 5 people. Sync would work with more; the limit exists because one person's buffering holds up everybody, and past five that happens too often to enjoy.
An account is needed; opening a room and joining one are both free, with no card asked. How it works · All the questions, answered plainly