Where did you get that info from? According to Google's own docs as well as my own image generation tests via the API, it supports up to 4K natively for gemini-3.1-flash-image-preview (aka NB2).

It just defaults to 1K. But I didn't see anything in the docs stating that it's just a simple upscale for larger resolutions.

https://ai.google.dev/gemini-api/docs/image-generation#gener...

▲ gpt5 3 hours ago | parent [-]

From: https://aistudio.google.com/models/gemini-3-pro-image

> Produce production-ready assets with native 1K output and built-in upscaling to 2K and 4K resolutions

The API doc you linked is misleading.

	▲	vunderba 2 hours ago \| parent [-]
		Yeah - if that's true then it's even worse because the output price says `$0.067 per 1K image, $0.101 per 2K image, and $0.151 per 4K image*.` But if all the "compute time" is spent on a 1K image and they're just passing it to a ESRGAN or other upscaling technique, then there’s literally zero reason to generate anything above 1K. Just save the money and upscale it yourself.