Aspect Ratio

Canvas proportions in Nano Banana Pro 2—what the picker offers vs. extra ratios in Google’s Gemini image API.

Ratios available in this app

The editor’s aspect ratio control matches the product configuration:

RatioTypical use
1:1Avatars, Instagram square, icons
3:4 / 4:3Print-friendly portrait / landscape stills
2:3 / 3:2Classic photo proportions
16:9Thumbnails, slides, desktop banners
9:16Shorts, stories, vertical social
21:9Cinematic letterbox, ultrawide

If a workflow doc mentions 4:5 (common on some social apps), it is not in the current picker—use 3:4 or 9:16 and crop in post if the platform demands 4:5.

Official Gemini / Nano Banana ratios (API reference)

Google documents additional aspect ratios for Gemini 3.1 Flash Image preview, including 1:4, 4:1, 1:8, and 8:1 alongside the usual set. Those are relevant when calling the API directly; the in-app list may be a subset. Full tables and pixel sizes are in Gemini API — image generation.

How ratio affects composition

Square (1:1) pulls attention to the center; edge detail competes with the middle.

Ultrawide (21:9) rewards layered depth; a single tiny subject often feels lost.

Vertical (9:16) suits one hero subject, product macros, or layouts with top/bottom UI safe zones.

Ratio and lens language

Ratio and “lens feel” are independent but interact: wide-angle language reads strongest in 16:9 / 21:9; compression language reads clearest in taller frames like 2:3 / 3:4.