How long should a DOOH spot be? Loop, slot and the six-second rule
Published · 4 min read
A spot that wins the room in an agency meeting plays out differently on a screen at a railway station. There it shares the screen with five to ten other creatives, gets its place in the loop and is gone again after a few seconds. Build it without that in mind and what runs outside is a fragment.
The rules are not complicated. What matters is applying them before sign-off. After sign-off, every correction means a re-edit.
1. Slot and loop set the frame
A digital screen plays creatives one after another. The time a single creative gets is the slot. The time until the same creative comes round again is the loop. A typical loop runs one to two minutes, with slots of six to ten seconds inside it. In malls or on platforms, where people stand and wait, slots are often longer. At the roadside, where people drive past, they are shorter.
The slot is the hard limit. A spot that runs longer gets cut off or is not accepted at all. A shorter one gives away paid time.
30-second test: ask the media owner for the slot length before you build and put it in the file name. It sounds trivial, but it prevents the most common re-edit.
2. The message belongs in the first half
Hardly anyone watches a DOOH spot from start to finish. A passer-by glances up at some point, usually mid-spot, and looks away again after two or three seconds. Show the brand or the offer in second eight and you reach only the few who happened to be looking from second one.
Brand, offer and visual idea should therefore be on screen by the halfway point at the latest, and stay there. After that the spot can vary, but it should not deliver anything important.
30-second test: run the spot on the digital screen and pause at the halfway mark. Is it clear from the still who is advertising and what for? If not, the pacing is too slow.
3. Six seconds is not a shortened ten
A common mistake is to speed up the ten-second spot for the six-second screen, or to trim it at the front and back. Neither works well. Cuts that fast cannot be read from twenty metres, and a trimmed spot often loses exactly the shot with the logo.
It is better to build a proper six-second version with one image, one line of text and the sender. One change of scene is enough, two is the ceiling. The spot looks calmer on the screen that way and is more likely to stick.
30-second test: put both versions side by side on the same screen and look at them with your phone in your hand. Which one do you understand at first glance?
4. The picture may move, the text should not
Motion draws the eye, and that is the big advantage digital screens have over paper. But when the text moves too, it becomes unreadable. A line that is flying into frame just as someone looks up is, for them, a swipe with no content.
A clear split has proved itself: the picture moves, the text stays put. Alternatively the text builds in the first second and then holds. Both give the eye time.
30-second test: watch the spot on the screen and try to read the text aloud while it plays. If you stumble, so does the passer-by.
5. Your spot does not run alone
In the loop your creative follows one and precedes another. If all three use a white background with red type, they blur into a single picture. If your spot opens dark and the one before it ends dark, the passer-by sees a black screen for a moment and looks away.
You cannot control the loop. You can make sure your spot is clearly a new creative in its first second, though. A distinct colour change and a decisive opening shot are enough. Avoid a slow fade up from black.
30-second test: in the preview, start your spot directly after any other creative. Do you notice the change straight away?
6. There is no sound, and no subtitles either
Almost all DOOH screens run silent. A spot taken over from TV loses its voice-over, its music and often its punchline. What remains has to work from the picture alone. A line of text can stand in for the voice-over if it is large enough to be read from a distance.
30-second test: watch the spot muted and shrink the preview to phone size. Can you still tell what it is about?
Why this belongs before sign-off
All six checks need the spot on the screen, at its size and in its surroundings. On top of that you need a quick way to hold a variant up against it. A mockup PDF cannot do that. It shows a still, and every variant starts the round again.
In a live simulation you upload the spot, choose the screen and watch it run. Checking the slot, pausing at the halfway mark, comparing two versions and looking at it from a distance takes a few minutes in total, before the file goes to the media owner. At the end you have an export you can hand straight into approval.