Quality
Resolution (1K / 2K / 4K) in Nano Banana Pro 2 and how it lines up with Google’s Gemini image API.
What the quality picker controls
In this app, quality maps to output resolution, not a separate “steps” slider. The standard options are 1K, 2K, and 4K.
Google’s Gemini 3 image models document the same idea under imageConfig.imageSize: values 512, 1K, 2K, 4K (use uppercase K in API examples). The 512 tier is called out for Gemini 3.1 Flash Image preview in the official image generation guide.
Model-specific limits
Some providers cap resolution. In this codebase, the base google/nano-banana path is 1K-only; Nano Banana 2 / Pro tiers can use 1K / 2K / 4K when the UI offers them. If a resolution snaps back to 1K after a model change, that is expected for locked tiers.
When to use each tier
| Tier | Best for |
|---|---|
| 1K | Fast iteration, layout tests, chatty exploration |
| 2K | Social heroes, web full-width, light print |
| 4K | Large print, heavy crops, fine text in frame |
Speed vs. quality
- Explore at 1K until composition and prompt are stable.
- Step up to 2K / 4K for the export you ship.
- For A/B tests, keep model + resolution + ratio constant so comparisons are fair.
SynthID
Google states that images from Nano Banana / Gemini native image generation include SynthID watermarking. Treat outputs like any other AI asset for disclosure and policy checks.
See also
- Aspect ratio for canvas shape.
- Create your first image for a practical first run.