Chrome Web Store 440x280 promo tile: generate at 1760x1120

You cannot request 440x280 from GPT Image 2.5 on Sume, because 123,200 pixels is below the 655,360 minimum. Request 1760x1120 instead: it is exactly 4x each edge (same 11:7 ratio) and passes every rule, then scale it down by 4 on your side.

Chrome's figures are from its Web Store images page; the size rules from OpenAI's guide and the Sume Image API docs. All read 2026-10-01. The 1760x1120 arithmetic is ours.

What does the Chrome Web Store want?

The page lists a small promo tile of 440x280 as required, and advises avoiding text on it. It also lists an optional 1400x560 marquee, and a 128x128 PNG icon.

Why does 440x280 fail?

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?

Chrome advises no text on the tile, so describe the picture only.

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": "Friendly abstract illustration of a browser tab with a lightning bolt, flat colors, no text",
    "image_size": "1760x1120",
    "output_format": "png"
  }'

How do I get to 440x280?

Resize the finished PNG by a factor of 4 in your own tool. Because 1760/4 = 440 and 1120/4 = 280, nothing needs cropping. Sume's docs do not describe a built-in resize for GPT models.