How Long Should an Educational Video Be?

What is the ideal length for an educational video?

About 6 minutes or less. Across 6.9 million video sessions on edX, the median time viewers spent watching was at most 6 minutes regardless of how long the video was, and viewers often did not reach the halfway point of videos longer than 9 minutes (Guo, Kim and Rubin, 2014).

Read that carefully: it measured how long people watched, not how much they learned. It is still the best evidence we have that long self-paced videos lose their audience, and it matches every creator's analytics. The practical rule is to plan one idea per video and keep each one short.

Does the style of the video change how long students watch?

Yes. In the same edX study, students watched tutorial videos in which a tutor draws on a tablet 1.5 to 2 times longer than slide-based or code-based videos (Guo et al., 2014).

Drawing the explanation as it is spoken keeps the eye on the idea being explained. That is the principle behind whiteboard-style explainers, and it is why DistilBook's Guided Explainer reveals each drawing at the moment the narration reaches it.

Should long lessons be split into shorter videos?

Yes. Breaking a lesson into short parts the learner moves through at their own pace improved learning in 7 of 7 experiments, with a median effect size of d = 0.67 (Mayer, 2023).

For a course, that means a 40 minute topic becomes six or seven short videos, each ending at a natural pause. For exam prep, one concept per video makes revision targeted: a student can rewatch exactly the step they got wrong.

Do quizzes between video segments help?

Strongly. In a study of a 21 minute recorded lecture, short quizzes between segments cut mind wandering to 19% (from about 40%), and final test scores reached 90%, against 76% for re-study and 68% for no quiz (Szpunar, Khan and Schacter, 2013).

Short videos make this easy: put a two-question check between them in your course platform or class.

How do I make short educational videos from material I already have?

Split your notes or textbook chapter by concept, then turn each part into its own video. In DistilBook you upload the PDF, choose the pages for one concept, set a short Length, check the narration, and generate. The first narrated slide is usually ready in about 6 minutes.

Sources

Every number on this page comes from the studies below.

• •Guo, P. J., Kim, J., and Rubin, R. (2014). How video production affects student engagement: an empirical study of MOOC videos. ACM Learning at Scale. pg.ucsd.edu/publications/edX-MOOC-video-production-and-engagement_LAS-2014.pdf
• •Mayer, R. E. (2023). Research-based principles for designing multimedia instruction. Society for the Teaching of Psychology.
• •Szpunar, K. K., Khan, N. Y., and Schacter, D. L. (2013). Interpolated memory tests reduce mind wandering and improve learning of online lectures. PNAS 110(16).