The 8-second rule: where viewers leave your video

Viewers rarely leave because a video is bad. They leave when nothing new happens for too long. Here is the rule we now apply to every timeline.

When we looked at the audience retention curve of our World War II map film, the drops did not come at random. They lined up with stretches where the screen kept moving but nothing new was happening: no new event, no new number, no new voice.

The rule

No stretch longer than 8 seconds without something new. "New" means a real change the viewer can notice: a new place on the map, a number, a photo, an archive voice, a caption, a sound. Camera moves on their own do not count.

How we check it

Before rendering, we list every event in the timeline in seconds and look for gaps. Anything over 8 seconds is fixed before the video goes out. We also flag a slow start (the first real beat after 3 seconds), long chapters (over 40 seconds) and long outros.

What you can do today

Open your last video, watch it with the sound off and count the seconds between changes. Wherever you reach eight, add a beat: a label, a zoom to the detail you are talking about, or a cut to the next idea. Then compare the retention curve of your next video with this one.