Storyline: How Course Content Is Preloaded

We want courses to play as smoothly as possible, so Storyline preloads slides to prevent interruptions. Here’s how slides and assets are downloaded as learners navigate through a course.

How Slides Are Preloaded

1. Storyline loads the first slide so the course can begin playing right away.
2. Storyline tries to anticipate where learners will go next based on the slide order in Story View. Storyline then preloads the next three slides so learners won’t experience delays. Here are some examples.
   
   In a linear course, Storyline preloads slides 2-4 while learners interact with the first slide.
   
   If the first slide gives learners the choice of branching to, say, five different scenes, Storyline preloads the first slide for the first three of those scenes. In a branching scenario like this one, you might want to avoid putting heavy objects, such as video files, on the first slide in each scene in case learners choose a slide that Storyline hasn’t preloaded.
   
   If the learner chooses a different path and jumps to a slide that hasn’t preloaded yet, Storyline immediately loads that slide so it’ll start playing right away. Then the download logic starts over, and Storyline preloads the next three slides from the learner’s current position in the course.
3. Slides continue to download according to the slide order in Story View and the path learners take through the course. Storyline tries to keep three slides preloaded to prevent playback delays.
   
   Slides download one at a time, not simultaneously. For example, Storyline won’t preload slide 3 until slide 2 has finished downloading. If a slide has lots of heavy objects or a learner’s internet connection is slow, the learner might see a brief pause in playback if Storyline hasn’t had time to preload all the assets before he or she arrives at the slide.

How Assets Are Preloaded for Each Slide

Assets for each slide download in this order: 1) images, 2) audio tracks, 3) videos.

Note that videos preload like other assets in Storyline 360 and Storyline 3 courses. If you're publishing with adaptive video quality, Storyline 360 preloads the high, medium, or low streaming video quality depending on the learner's internet speed.