AI Video Aspect Ratio Guide
Aspect ratio changes composition, camera movement and how much room a subject has to move. Choosing it before generation usually produces cleaner framing than cropping a finished clip afterward.
16:9
YouTube, cinematic presentations, desktop-first ads
Best when lateral camera movement and environment width matter.
9:16
TikTok, Reels, Shorts, mobile ads
Keep important action near the vertical center and plan less sideways travel.
1:1
Feeds, product loops, flexible social reuse
Works well for centered products and compact subject motion.
4:3 / 3:4
Editorial, retro, portrait-heavy workflows
Useful when the model or reference composition benefits from a less extreme frame.
What this page is meant to answer
Use AI Video Aspect Ratio Guide for explanation, setup choices and workflow checks rather than immediate prompt generation. It is the informational layer for this specific search intent.
Scope boundary: Use the linked tool page when you are ready to build a prompt or calculate cost; keep this guide for the reasoning and setup.