FAQ

A tab appears in the list only after a video is actually playing in it. If yours isn't showing, check these.

Set up first: side by side, both playing

Put the two videos side by side — two windows, or a split screen — and press play on both. Then open ReactionSync.

One of the tabs is hidden, paused or muted

A tab sitting behind another one, with its video paused or muted, may not be picked up. Bring it into view, or unmute it and let it play.

Once they're paired, hide, mute and pause whatever you like — this only matters while you're setting up.

The video hasn't started

On sites like YouTube, Vimeo and Google Drive, a video will often sit showing a still frame with a play button over the middle of it. The page looks finished, but nothing has loaded. Click play and give it a second.

The page is still loading

Just wait — you don't need to close or reopen the popup. The tab shows up as soon as the video is ready.

Both are side by side and playing, and still nothing

This can happen if the page was open before ReactionSync was installed or updated. Chrome updates extensions on its own, so a tab that worked yesterday may need this today. Reload the page and press play again.

You're not on the page the video plays on

A search page, a browse page, or the description page for a film or episode won't appear in the list, even on a site we support. You need to be on the page where the video itself is playing.

After picking your tabs you choose one of two ways to begin.

Start from Beginning jumps both videos to the first sync point and plays from there. Use it when you're sitting down to watch the whole thing.

Continue from Current Source Time leaves the source where it is and brings the reaction to match. Use it if you're already part-way through, or if you paired late.

Either one. Play, pause or seek on the source or the reaction, and the other follows on its own.

You don't need to keep the extension open while you watch.

Linked is the normal state. It means the two videos are tied together — pause one and the other pauses, seek one and the other follows.

Turning it off breaks that tie and lets you move each video on its own. There's one reason to do it: you're lining two videos up by hand and want to scrub freely without the sync pulling them back together while you work.

Turn it back on when you're done.

They skip both videos at once by the number of seconds in the box beside them.

Because the session is linked, moving one moves the other — so you can jump back thirty seconds to catch something without the two coming apart. Set the number to whatever suits; it applies to every skip until you change it.

That's the drift meter. It sits in the top right corner of the reaction video and shows how closely the two are tracking each other.

Green means they're in sync. Red means they've slipped apart.

If it goes red, pause and play again — that forces both videos to snap back together.

You can switch it off in the extension with the Drift Meter checkbox if you'd rather not see it.

Not with the player's own speed control. Syncing assumes both videos are playing at normal speed, so leave the source and the reaction at 1x.

If either one is set to 1.5x or 0.75x, the two will drift apart. Set both back to 1x if that happens.

There is one exception, and it's built into the extension rather than the player — see videos slowly drifting apart.

The session ends. The other tab shows “Sync Connection Lost” and playback stops being tied together.

This is deliberate. Refreshing or navigating replaces the video the extension was tracking, and carrying on against the wrong one would put you out of sync without telling you.

Start the two videos again and pair as normal. If you were using a sync script it's still there — nothing is lost but the session itself.

Open the extension and click End Session. The two videos go back to being independent, and both tabs carry on playing whatever they were playing.

Closing either tab ends the session too.

A saved record of how one reaction lines up with its episode or film: where they match, where the reactor stops the show to talk (the show waits), where the reaction skips part of the episode (the reaction waits), and where it ends. Inside the extension it's called a sync script.

Without one, you pair two tabs and mark the moment they match. With one, that's already done — open the link, pick your two tabs, and you're watching.

You can make your own once you've paired something: save it as a file, or as a link you can send to someone.

Anyone can make one: the reactor, a fan, or us. A creator marks the sync points once, saves a link, and posts it alongside the reaction — after that, anyone who follows them can press play without setting anything up. If there isn't one for a reaction you want to watch, ask the reactor, or send us the reaction and the episode at support@reactionsync.com and we'll make it.

Open both videos in their own tabs, side by side, and press play on each. Copy the sync link (on its page, Copy sync link). Then open the extension, pick the two tabs, click Continue and choose Load from Link. Paste the link and click the arrow, and it starts.

If you were sent a .sync file instead, use Load .sync File & Start and pick it from your computer. Same result.

Either way the alignment comes from the script — there's nothing for you to mark.

Pair the two tabs, then click Edit Script in the extension to open the timeline.

Before you start scrubbing, turn Linked off. While it's on, the sync engine keeps pulling the two back together, which fights you as you try to align them by hand. With it off, you can move each video freely.

Find a moment that appears in both, add a sync point there, and turn Linked back on to check it. When you're happy, save the script as a file or share it as a link.

Most reactions need only the first one. The others handle stretches where the two videos aren't running together.

Synced

The two line up here and play together from this point on. This is the normal one.

Source Paused

Freezes the source while the reaction keeps playing. Use it where the reactor pauses to talk about something.

Reaction Paused

The opposite — the reaction waits while the source plays on. Use it where the reactor skips ahead or watches a stretch without commenting.

End

Stops the session where the reaction finishes. Worth adding: without it, the site's own autoplay can start the next episode and carry the session off with it.

If they start together and get steadily further apart — rather than jumping out of sync at one moment — the two copies are almost certainly running at slightly different frame rates. A television cut at 25fps against a cinema cut at 24fps will separate a little more every minute.

In Edit mode, use the Videos playing at different speeds? dropdown to apply a correction. It adjusts the reaction's speed by a small amount to match, and it's saved with the script so anyone using it gets the same correction.

Two ways, from the extension once you've marked your sync points.

Share Script uploads it and gives you a link. You're asked for a title, the creator's name, the two video addresses and any notes — all of which the person opening the link sees, so they know they've got the right one. Post the link wherever the reaction lives.

Export .sync saves it as a file instead. Better for sending to one person, or keeping a copy.

Click your profile picture in the extension and choose My Shared Scripts. Everything you've uploaded is listed there, with its link.

The full list is on the homepage, kept up to date as we add more.

You watch on your own subscriptions. ReactionSync doesn't host, provide, or unlock any content.

Not on Prime Video: its ad breaks and the studio intros that vary by region are both handled for you.

On Netflix, Crunchyroll and JioHotstar, use an ad-free plan, because ads there aren't handled. If ads on a service you use matter to you, tell us at support@reactionsync.com: we build what viewers ask for.

Your account holds your free access and, later, your subscription, and keeps them with you if you reinstall or switch computers.

It's the standard "Sign in with Google" on Google's own page, so we never see your password. Google shares only your name, email address and profile picture, and lists them on its screen before you agree. ReactionSync gets no access to your YouTube, Gmail, Drive or anything else in your Google account.

Google's window shows a supabase.co address rather than ReactionSync: that's our sign-in service, and it's expected. When the window closes, click the ReactionSync icon again to carry on.

The details are in our privacy policy.

30 days from the day you sign in with Google. No card, and nothing held back — you get the whole product.

After that you'll need a paid subscription to carry on. Current rates are on the pricing page.

We're still finding our feet on pricing, so if you're a reaction creator, or you've been using this and have thoughts on it, write to support@reactionsync.com. We're extending trials case by case for people willing to tell us what's working and what isn't.

In your browser, open the ReactionSync extension, click your profile picture in the top right, and choose Manage Subscription. Your account page opens, with a Cancel subscription button on it. That's all — you don't need to contact us.

Future charges stop straight away, and you keep access until the end of the period you've already paid for.

Details in the refund policy.