#Nano Banana 4K

14 messages · Page 1 of 1 (latest)

worthy nymph
#

Hi,

I'm trying to generate 4K images using
google/gemini-3-pro-image-preview but the
image_size parameter doesn't seem to be
respected.

What I'm sending:
{
"model": "google/gemini-3-pro-image-preview",
"messages": [{"role": "user", "content":
"..."}],
"modalities": ["text", "image"],
"image_config": {
"aspect_ratio": "16:9",
"image_size": "4K"
}
}

Result: Images are always ~1376×768 (1K
resolution) regardless of image_size value.

I also tried Google's native format
(generationConfig.imageConfig.imageSize) but
same result.

How do I access this feature?

Thanks

thin belfry
#

not available yet through OpenRouter

silver plover
#

Seems to be still not available? Any plans to support it? Otherwise it’s not practically useful.

thin belfry
#

cause there might be one of two cases from what i've learned

silver plover
#

I’m working with the chat interface. Tried a variety of parameters, as text prompt as well as json, none returned anything but the same 1376x768 images.

thin belfry
#

with what chat interface? one you made yourself or OpenRouter's chat or Open WebUI

#

first check if you're passing "4K" with a capital K, then check if you're getting all images generated in the response

#

the 4K image is just an upscaling, the model first outputs some mid-steps images in its reasoning

#

those images are 1K

#

#general message

silver plover
#

Open router Chat window. I will send the prompt example in a bit.

silver plover
#

{
"model": "google/gemini-3-pro-image-preview",
"messages": [
{
"role": "user",
"content": "Create a picture of a nano banana dish in a fancy restaurant with a Gemini theme"
}
],
"modalities": ["image", "text"],
"image_config": {
"aspect_ratio": "16:9",
"image_size": "4K"
}

Here is a test prompt, generated image is 1376x768