How video length affects performance (and how to script for it)

The short answer

A video should be as long as its idea and no longer. For short-form feeds, that usually means under a minute, with the point in the first second, because attention is short: Metricool’s 2026 study of 799,718 YouTube videos found the average Short was watched for about 16 seconds, about 67% less than a year earlier. Longer videos work when people chose to watch them, as on YouTube, and when every minute earns the next.

Platform rules also set limits on reach. Instagram allows Reels of up to 20 minutes, but says Reels over 3 minutes will not be recommended to new audiences. Keep a video meant to reach new people inside the length the platform will recommend.

Length limits by platform

The limits each platform states, from its own documentation:

Why shorter usually wins in feeds

Short-form feeds rank on whether people keep watching. TikTok names finishing a longer video from beginning to end as a strong signal; Instagram lists watching a reel all the way through among its most important Reels predictions; Meta’s Facebook Reels system predicts how long you will watch and whether you will watch to completion. A 20-second video people finish sends a stronger signal than a two-minute one they leave halfway.

When longer works

Long videos work where people chose to watch: YouTube, where a viewer clicked a title, and where YouTube weighs watch time by how much viewers valued it. Tutorials, reviews, stories and explainers earn their length if every section moves the viewer forward. Use the long video as the main piece, and cut Shorts and Reels from it to send people there; Metricool found channels posting about 5 Shorts a month had long videos averaging 46% more views than the study’s overall average.

A script that holds attention

A structure that works for most short videos:

• Hook, first second: the result, the question or the moment, on screen and spoken.
• Promise, next few seconds: what the viewer will get by watching.
• Body: one idea, in steps or a story, each line moving it along. Cut anything that does not.
• Payoff: deliver the promise clearly, near the end.
• Next step: one ask, such as follow for part two, save it, or watch the full video.

Writing the script

Write the way you speak, in short sentences, and read it aloud before filming. Mark where each shot changes and what appears on screen, and add on-screen text for the key line, since many people watch without sound. For a 30-second video, about 70 to 80 spoken words is a comfortable pace; if the script runs longer, cut ideas, not pauses.

Length by purpose

Decide the length from the job the video does. A video meant to reach new people should be short and land its point early, inside the length the platform recommends to non-followers. A video for people who already follow you can run longer, since they chose you. A tutorial should be exactly as long as the steps, and a story as long as it stays interesting. A product demo is usually best under a minute, with a link to more.

Test length against your own videos

Averages are a starting point. Make the same kind of video at two lengths over a few weeks and compare average watch time, completion and shares with your own median. YouTube’s retention report shows exactly where viewers leave, which tells you what to cut next time.

Questions

Sources

1. Metricool, YouTube trends 2026: what 799,718 videos tell us about views, Shorts, and watch time, July 2026.
2. Instagram, Record a reel on Instagram, checked October 2026.
3. YouTube, Get started creating YouTube Shorts, checked October 2026.
4. YouTube, Upload videos longer than 15 minutes, checked October 2026.
5. TikTok, Content Posting API: direct post reference, checked October 2026.
6. Meta, Reels publishing, Video API, checked October 2026.
7. X, Media best practices, X API documentation, checked October 2026.
8. LinkedIn, Video sharing troubleshooting, checked October 2026.
9. Pinterest, Review Pin specs, checked October 2026.