The proportional relationship between an image's width and height.
Aspect ratio is the proportional relationship between an image's width and height, written as two numbers like 1:1 for square, 4:5 for portrait, or 16:9 for wide.
Choosing the right ratio matters because each channel favors different shapes: square and portrait for social feeds, wide for banners and video. Generating or reformatting to the correct ratio keeps your subject well-framed everywhere.
Square (1:1) and portrait (4:5 or 9:16) tend to perform best in feeds and stories. Wide (16:9) suits banners and video.
Yes, with outpainting, which extends the scene to fit a new ratio instead of cutting the subject.