Edge Add-ons 1400x560 promo tile: generate 2800x1120 and halve

1400x560 is not a legal GPT Image 2.5 size, because 1400 / 16 = 87.5. Request 2800x1120 instead: both edges are multiples of 16 (175 x 16 and 70 x 16), the ratio is exactly 5:2 like 1400x560, and it has 3,136,000 pixels. Halve it to get 1400x560.

Edge's sizes are from its Partner Center publishing page; the rules from OpenAI's guide and the Sume Image API docs. Read 2026-10-01; the arithmetic is ours.

What does Edge ask for?

Edge's store listing table says the large promotional tile is optional, with PNG files of 1400x560. The small promotional tile is 440x280. The extension logo is 1:1, 300x300 recommended and 128x128 minimum. Screenshots are 640x480 or 1280x800, up to 6.

Why 2800x1120?

OpenAI's guide lists the GPT Image 2.5 custom-size rules: both edges multiples of 16, edges at most 3840, aspect ratio between 1:3 and 3:1, and 655,360 to 8,294,400 total pixels. Sume's Image API docs state the same limits for image_size on GPT models.

What do I send?

Request png, since Edge lists PNG for this tile.

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": "Wide promo banner, abstract shapes in teal and orange, empty space on the left third, no text",
    "image_size": "2800x1120",
    "output_format": "png"
  }'

Is the large tile required?

No. Edge marks it optional; the logo and description are the required items per language. Check the page again before submitting, since the listing rules can change.