"How long should my video be?" is the most common question I get, and the answer is almost always "shorter than you think". Every platform has a sweet spot where retention peaks, and most businesses overshoot it by a factor of two or three.
Here are the numbers I actually use, based on my own testing and industry data.
YouTube
8-12 minutes for educational content. Not 3 minutes, not 30 minutes. YouTube's algorithm rewards longer watch time, but only if retention stays above 40%. Eight to twelve minutes is the zone where most creators can maintain engagement without padding.
For product demos and ads: under 90 seconds. Nobody watches a 5-minute ad on YouTube voluntarily.
Reels: 15-30 seconds. The algorithm favors short. Anything over 45 seconds bleeds viewers.
Stories: 5-10 seconds per frame. Any longer and people tap through. Break a longer message into multiple frames.
Feed: honestly, skip it. Instagram feed video engagement is terrible right now.
TikTok
15-60 seconds. The longer you go, the more the algorithm punishes you. If you have a 90-second idea, cut it into two videos instead.
The first 3 seconds are everything. If the viewer is still there at the 5-second mark, the algorithm will show your video to more people.
30 seconds to 2 minutes for organic feed video. This is one of the few platforms where medium-length works. Longer than 2 minutes and completion rate crashes.
Native uploads get 5x the reach of YouTube embeds. Do not link out to YouTube from a LinkedIn post — upload the video directly.
Landing pages
60-90 seconds for a homepage video. 2-3 minutes for a detailed product explainer. Anything longer and visitors close the tab.
Always add captions. Half of your visitors are watching with sound off.
Email embeds
Trick question — do not embed video in email. Most email clients break it. Use a thumbnail image with a play button that links to a landing page with the video. Click-through rates are 2-3x higher this way.
The general rule
Make it as short as possible while still delivering the value. If you can say it in 30 seconds, do not stretch it to 60 to "seem professional". Tight, punchy videos outperform bloated ones on every platform. Always.
For more on hooking viewers in those crucial opening seconds, see Writing Video Scripts That Actually Sell.