The best length for short-form video

Completion rate beats raw length

Every short-form algorithm optimizes for watch time relative to length — in other words, completion rate. A clip people finish (and re-watch) signals 'show this to more people.' A longer clip with the same absolute watch time but lower completion gets throttled. So the goal isn't to hit a magic number of seconds; it's to make every second earn the next one.

Platform-by-platform sweet spots

These are starting points, not rules. Test against your own audience.

• TikTok: 21–34 seconds is a reliable pocket for single-idea clips. Long enough to land a point, short enough to loop.
• Instagram Reels: 15–30 seconds. Reels lean even shorter; the feed is unforgiving of slow starts.
• YouTube Shorts: 20–45 seconds. Shorts viewers tolerate slightly more, especially for how-to and story content.

Hook in the first second, cut at the payoff

Whatever the length, the first second decides the rest. Open on the most interesting moment, not the setup. Then end the instant the point lands — trailing dead air at the end is the most common reason a good clip underperforms.

When in doubt, cut it shorter

If you're unsure between two edits, ship the shorter one. You can always post a longer version later, but a tight clip almost never loses to a loose one. Tools that auto-detect the strongest window and trim internal dead air make this the default instead of extra work.