Coupang main image: white background, square, 95% fill

Coupang Global Sellers says the standard main image has a white background, is square, and shows the item at a clear angle, taking up about 95% of the space. With Sume you can request the square with aspect_ratio: "1:1"; the 95% fill and the pure white are things you ask for in the prompt and then verify.

Coupang guidance is from its Seller University page (undated) and request options from Sume's image docs, both read 2026-10-01.

What does Coupang say about the main image?

The page names a few points; the ones that bear on an image request are below.

Which request options matter?

Use aspect_ratio: "1:1". The docs list it among the normalized ratios. For a file type, output_format takes png, jpeg, webp or svg; pick png or jpeg for a flat white listing image. Transparent output is not what you want here, and the docs say background: transparent is listed for ChatGPT Image 2.5, so an opaque request is the safer match for a white backdrop.

Custom pixels, if you need a larger square, follow the rule that edges are multiples of 16, max edge 3840, aspect at most 3:1, and 655,360–8,294,400 pixels, for example 2048x2048.

How do I get the item near 95% of the frame?

Say it in the prompt: a single item centered, filling almost the whole square, plain white backdrop, no props, no extra items. Then measure the result. If the item is small, crop and re-square it outside Sume, or regenerate with tighter framing. A product shot from your own photo is usually closer to what shoppers will receive than a free-form generation; see AI product photo on white.

What should I check before uploading?

Confirm the image is square, the background is white, the item fills about 95%, and nothing appears that the listing does not include (Coupang warns against that). Check the logo is clear if you feature one, and that the image is your own original content under Coupang's IP policy.