Pre-roll

Pre-roll is the most familiar video ad format: you click play and an ad runs first. It appears on YouTube, news sites, streaming apps and CTV services. It can be skippable (often after five seconds) or non-skippable, and lengths commonly range from six to 30 seconds.

Because the viewer is waiting for content they actively chose, pre-roll tends to get high attention and viewability. It is the most common form of instream video on the web, and is usually delivered via VAST. Completion rates depend on skippability and length: non-skippable CTV pre-roll often completes at very high rates, while skippable mobile pre-roll completes far less often.

Pre-roll is priced by CPM, cost per view or cost per completed view. It competes with Mid-roll, which interrupts content, and post-roll, which follows it and tends to get lower attention. For short-form content, long pre-roll can drive viewers away, so publishers balance ad length with content length.

Think of it like this

Pre-roll is like the trailers before a film at the cinema: you are seated and waiting, so you usually watch them.

An example

A cooking channel in Turkey runs a 15-second non-skippable pre-roll before each three-minute recipe video, and a 6-second bumper before shorter clips.