Google Merchant Center image formats: which Sume output_format fits

Google Merchant Center lists JPEG, WebP, PNG, GIF, BMP and TIFF for product images. Sume's Image API lists output_format values of png, jpeg, webp and svg, so choose png, jpeg or webp; svg is not on Google's list.

Which formats overlap?

Google's page read on 2026-09-30 and the Image API docs compared.

Do all models accept every format?

No. The docs say a model only accepts the values its catalog descriptors list, and a setting it does not list is rejected with 400 unsupported_parameter. Read supported_parameters from GET /v1/images/models before you pin output_format.

How do I request a format?

Set output_format in the request; the response gives a media_type for each image, so log it.

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": "White sneaker, plain light background, product photo",
    "image_size": "1536x1536",
    "output_format": "webp"
  }'

Which one should I choose?

Use jpeg for photos on a filled backdrop and png when you need an alpha channel, both on Google's list. The docs list transparent as a background value on ChatGPT Image 2.5. Whether Google shows a transparent background as you expect is outside these docs, so check the listing preview.