Image Size Resource
At least 1000 pixel on either height or width
The recommended size for listing images is 2000px for the shortest side of the image, and a resolution of 72PPI. File < 1MB for smooth uploading.
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
The API supports a maximum image dimension of 15,000 pixels (width + height in pixels). If your image is less than 1,000 pixels (width + height in pixels), a warning is provided but the picture is not rejected.
For the best zoom-in functionality, size your images so they are between 800-1600 pixels on the longest side.
Recommend using images that are between 1500 and 2500 pixels wide
A resolution of at least 3,000px on the shortest side of your picture