Aspect ratio is width ÷ height of the creative frame (e.g. 1:1 square, 4:5 vertical feed, 9:16 Reels/Stories, 16:9 YouTube). Wrong ratio triggers cropping, letterboxing, or disapproval — the Validator checks uploaded files against live spec tables.
Safe zones matter on 9:16: keep logos and CTAs inside platform “safe area” guides.
Sources
Last verified Jun 3, 2026