Everyone tries the same thing first. You send the link, you both hover over the play button, someone counts down from three. It works for about four minutes.
Then one of you gets a mid-roll ad and the other doesn't. One of you is on hotel wifi and buffers for six seconds. Somebody pauses to answer the door. Every one of those moments adds a gap that never closes on its own, and you spend the rest of the video saying "wait, where are you?"
Why counting down never holds
The gap is not your reflexes. It is three things that have nothing to do with when you pressed play:
- Ads land at different moments. YouTube decides ad breaks per viewer. Two people watching the same video get different breaks at different times, and every break is 15 to 30 seconds of drift.
- Buffering is per connection. The slower side stalls, the faster side keeps going.
- Pausing is contagious but resuming is not. One person pauses and says "hang on"; you both restart, but not on the same frame.
None of that is fixable by being more careful with the countdown. It needs something watching both sides.
The three ways people actually do this
| Same-time clicking | Screen sharing | Synced playback | |
|---|---|---|---|
| Video quality | original on both sides | re-encoded, usually worse | original on both sides |
| Who needs the link | both | only the person sharing | both |
| Stays in sync | no | yes, one stream | yes, corrected continuously |
| Ads | drift you apart | shared | one side waits |
| Upload load | none | heavy on the sharer | none |
Same-time clicking is free and needs nothing, and it is why you are reading this page.
Screen sharing on Discord, Zoom or Meet does keep you together, because there is only one video — but you are no longer watching YouTube, you are watching a compressed recording of someone's browser window. Quality drops, audio drifts from the picture, and the person sharing pays for it in upload bandwidth and a hot laptop.
Synced playback leaves both of you on the real video, in your own browser, at full quality, and continuously corrects the gap between you. That is what our extension does, and the rest of this page is how to set it up.
Setting it up
- Both people install the extension. It is a Chrome extension — download it here. Chrome 116 or newer; Edge, Brave and Opera are expected to work but we have not verified them, and Firefox and Safari are not supported.
- One of you opens the video and starts a room. You get an 8-character code, something like
k7mq2xw4. - Send the code however you like — message, call, whatever you are already using.
- The other person joins with the code and opens the same video. If they are somewhere else, the panel offers "Open the video" and one click takes them there. Nobody gets redirected without pressing it.
- Press the purple sync button. Both sides count down 3 seconds and start on the same instant.
From then on, each side reports its position once a second. If a gap opens, whoever is behind speeds up by 2 to 5 percent until it closes — a change you will not hear. The target is under 250 milliseconds, and while the drift indicator in the panel is green, you are there.
When an ad starts, the other person waits
This is the part that makes the difference over a two-hour video. Ads on YouTube are detected, so while you are in an ad break the other side pauses and waits for you. When you are both clear, you both resume together.
The same applies to buffering: if the slower side stalls for more than 700 milliseconds, the other side pauses and both continue together. If someone is buffering constantly, the fix is lowering the video quality on that side, not restarting the room.
Two honest limits here. Ads are detected on YouTube, JW Player and Video.js — those cover a large part of the web, but not all of it. In a player we do not recognise, an ad looks like a normal pause to the other person, and you may need to press "Sync now" afterwards.
Chat without leaving the video
You can talk in the panel, and with the panel closed and the video fullscreen an incoming message shows in the corner of the video for six seconds. With the panel closed you also get a Chrome notification. Messages are never stored on the server — they are relayed and gone; your own device keeps the last 200 for the browser session and clears them when you close the browser.
Most people still keep a voice call open alongside. Text is for "this part" and "did you see that", not for a two-hour conversation.
Before you start, the things worth knowing
- It works on any page that has a video element — YouTube, Vimeo, Twitch, news sites, embedded players. It hooks the page's own player rather than integrating with one service.
- Netflix, Disney+ and Prime Video work. DRM protects the content, not the play/pause controls, so a protected service is not out of reach. The service-by-service picture is here.
- Rooms hold at most 5 people. Sync would work with more; the limit is there because one person's ads and buffering hold up everyone, and past five that happens too often to enjoy.
- The video never goes through our server. Everyone plays it in their own browser with their own account; only small messages — position, play state, chat — pass through.
- It needs an account, and it is free. Opening a room and joining one cost nothing, and no card is asked. Accounts and price, answered plainly.
If you want the whole picture of how the timing works before you install anything, that is written out in how it works.