Resolutions

The resolution field selects the output size. Accepted values are 1K, 2K, and 4K.

Info

resolution applies only to gemini-3.1-flash-image and gemini-3-pro-image. gemini-2.5-flash-image always outputs 1K and ignores the field.

Model	resolution field	Output
gemini-2.5-flash-image	Not accepted	Always 1K
gemini-3.1-flash-image	1K · 2K · 4K	Selected value
gemini-3-pro-image	1K · 2K · 4K	Selected value