Why are AI videos only 10 seconds long?
Quick Answer
Mainly because AI models drift over time: trained on real footage but running on their own output, small errors compound frame by frame until motion and faces break down. Long clips are also compute-heavy, so tools cap them short — Veo at 8 seconds, Kling's free tier at 10, Sora 2 at 15–25. It's a per-clip limit, not AI video's overall ceiling.
It's error build-up, not just compute cost
The main reason is error accumulation. These models are trained on real frames but generate by feeding on their own output, so small mistakes compound frame by frame — motion drifts, faces warp, and scenes eventually "collapse." Generating long clips also costs far more compute and memory. That's why single-clip caps stay short: Veo at 8 seconds, Kling's free tier at 10, Sora 2 at 15–25. But it's only a per-clip limit — longer videos come from stitching many clips, via extend features (Runway, Kling) or scene-based platforms.