> ## Documentation Index
> Fetch the complete documentation index at: https://docs.yingtu.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Gemini 3 Pro Image parameters

> Configure 1K, 2K, or 4K Nano Banana Pro generation and editing requests and handle large responses safely.

Pro uses the same Gemini-native body as Flash, with different YingTu prices and
a stronger reason to consider asynchronous execution for large output.

| Field                | Value for this model                      |
| -------------------- | ----------------------------------------- |
| Model path           | `gemini-3-pro-image`                      |
| `imageSize`          | `1K`, `2K`, or `4K`; omitted means 1K     |
| `aspectRatio`        | Optional; `1:1` was verified at 1K and 4K |
| `responseModalities` | Include `IMAGE`; `TEXT` is optional       |
| `candidateCount`     | Omit or use `1`                           |
| 1K / 2K / 4K price   | USD 0.050 / USD 0.050 / USD 0.090         |

```json theme={"system"}
{
  "contents": [{
    "role": "user",
    "parts": [{"text": "A precise exhibition poster with a disciplined grid"}]
  }],
  "generationConfig": {
    "responseModalities": ["TEXT", "IMAGE"],
    "imageConfig": {"aspectRatio": "1:1", "imageSize": "4K"}
  }
}
```

## Plan for Base64 size

The verified 4096 × 4096 JPEG contained roughly 7.4 MB of decoded image data;
the JSON Base64 string was larger. Set client, proxy, and log limits accordingly.
Do not retain full response bodies in ordinary application logs.

For a caller with a short timeout, submit the same body to
`:asyncGenerateContent` and move the completed image into storage you control.

## Editing input

Use `inlineData` for a source image and preserve its real MIME type. The live
1K edit returned JPEG output and optional text may still appear before it.

<Warning>
  A 4K request is billed at the 4K tier even when the prompt fails to use the
  extra resolution effectively. Validate at 1K or 2K before scaling 4K traffic.
</Warning>