Instacart lifestyle image: 1600x896 passes the 1067x600-1600x900 box

Instacart's display ads use a shoppable lifestyle image that is 16:9, between 1067x600 and 1600x900, JPG or PNG, at most 1 MB. On openai/gpt-image-2.5 a custom image_size needs both edges to be multiples of 16, and 1600x900 is not (900 / 16 = 56.25), so request 1600x896, which is inside the allowed box and about 16:9.

Instacart facts are from its display creative page, read 2026-10-01. Sume facts are from the Images API docs.

What are the Instacart limits?

How do I request it?

Use output_format: "jpeg", which is a smaller file than PNG for a photo. Sume v1 does not support output_compression or an explicit-pixel size, so you cannot tune the file size on the request; measure it after download.

curl -X POST "https://api.sume.com/v1/images" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-image-2.5",
    "prompt": "Family breakfast table with a bowl of oatmeal and fresh berries, natural window light, no text",
    "image_size": "1600x896",
    "output_format": "jpeg"
  }'

What do I still have to do?

Check the file is 1 MB or less. If it is larger, re-encode it in your own tool, because Sume cannot set compression. The ad copy (22 characters) and tagline (29 characters) are fields in Instacart's ad, so keep text out of the picture, as in the prompt above. Confirm current rules on Instacart's page. Marketplace sizes differ; for Walmart see the 2200x2200 post.