https://www.adobe.com/express/discover/sizes/instagram
image sizes
nstagram posts can be square, landscape, or vertical. All images will be cropped to a square in the feed. The ideal size for square posts is 1080px by 1080px at a 1:1 aspect ratio. For landscape posts, use an image that is 1080px by 566px, with an aspect ratio of 1.91:1. Vertical images should be sized at 1080px by 1350px with a 4:5 aspect ratio.