Sume image models that do not list the 4:5 Instagram ratio

A 4:5 portrait is the Instagram feed format: 1080 by 1350 pixels. The Sume Image API page is explicit that 4:5 is Instagram portrait and not 4:3, and that Banana Pro sends it natively. The model lists below come from the aspect-ratio catalog in the repository.

From the catalog data in the repo, the ids that do not list 4:5 are Imagen 4 Fast, Imagen 4 Ultra, Grok Image and Higgsfield Soul. Everything else, including both ChatGPT Image 2.5 variants, Seedream, Qwen, FLUX.2, Ideogram and Recraft, lists it.

Which models do not, and what to use

What a 3:4 fallback costs you

3:4 is slightly taller than 4:5. Cropping a 3:4 image to 4:5 trims a little off the top and bottom, so keep the subject out of the outer edge when you must use these models. Check the model's GET /v1/images/models descriptor before you send 4:5, so the miss shows up in testing rather than in a batch.

import os, requests
headers = {"Authorization": "Bearer " + os.environ["SUME_API_KEY"]}
r = requests.post("https://api.sume.com/v1/images", headers=headers, timeout=60, json={
    "model": "google/nano-banana-2",
    "prompt": "Feed post, centered product, soft shadow",
    "aspect_ratio": "4:5",
    "resolution": "1K",
})
print(r.status_code)

Exact 1080 by 1350

On Nano Banana, a 1080x1350 image size becomes aspect_ratio: "4:5" plus a job target_pixels; the model's native output is about 928 by 1152 at 1K and the exact 1080 by 1350 comes from a documented post-step. Check the dimensions you get back if the exact pixel size matters.

How this was checked

Vendor facts come from the pages listed in the sources, read on 2026-10-05. Sume facts come from the Image API docs and the catalog code on main on the same date. Catalogs and limits change, so read the descriptors from GET /v1/images/models before you pin a number in production code.