Veo 3.1 Aspect Ratio Guide
Aspect ratio changes the shot itself. A vertical frame needs different blocking and camera travel than a wide frame, so it is usually better to decide the delivery format before generation rather than crop blindly afterward.
How GenVideoKit structures Veo 3.1 prompts
Use coherent natural-language direction with explicit temporal flow from start state to end state. Describe subject action, camera behavior, lighting and environmental motion. When relevant, integrate dialogue, ambience and sound effects because this model family supports native audiovisual generation. Avoid conflicting camera moves and keep continuity physically plausible.
Production shortcut
Choose the final delivery ratio before generation when possible. Reframing after the fact is useful for secondary versions, but it cannot recover composition that was never generated.
16:9
Useful for wide compositions, landscape movement, YouTube and cinematic delivery. Give lateral action enough room to travel.
9:16
Build vertically from the start for Reels, Shorts and TikTok. Keep faces and products away from extreme top and bottom crop zones.
1:1
Works for centered product and social compositions. Avoid camera travel that depends on wide horizontal space.