> ## 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 3.1 Flash Lite Image parameters

> Configure 1K generation and editing requests for gemini-3.1-flash-lite-image with Gemini-native fields.

Lite accepts the shared Gemini-native body and one output size. Keep
`imageSize` uppercase when it is present.

| Field                | Value for this model                |
| -------------------- | ----------------------------------- |
| Model path           | `gemini-3.1-flash-lite-image`       |
| `responseModalities` | Include `IMAGE`; `TEXT` is optional |
| `aspectRatio`        | Optional; YingTu verified `1:1`     |
| `imageSize`          | Omit or use `1K`                    |
| `2K` / `4K`          | Unsupported                         |
| `candidateCount`     | Omit or use `1`                     |
| YingTu price         | USD 0.025 per request               |

```json theme={"system"}
{
  "contents": [{
    "role": "user",
    "parts": [{"text": "A clean product thumbnail with a single object"}]
  }],
  "generationConfig": {
    "responseModalities": ["TEXT", "IMAGE"],
    "imageConfig": {"aspectRatio": "1:1", "imageSize": "1K"}
  }
}
```

## Fast editing input

The upstream model is designed for local edits such as color swaps, stickers,
and background changes. YingTu verified the same inline input shape used by the
rest of the family:

```json theme={"system"}
{
  "contents": [{
    "role": "user",
    "parts": [
      {"text": "Preserve the object and change only the surface color"},
      {"inlineData": {"mimeType": "image/png", "data": "BASE64_SOURCE_IMAGE"}}
    ]
  }],
  "generationConfig": {
    "responseModalities": ["TEXT", "IMAGE"],
    "imageConfig": {"aspectRatio": "1:1", "imageSize": "1K"}
  }
}
```

<Warning>`imageSize` is case-sensitive. Use `1K`, not `1k` or `1024px`.</Warning>

The verified responses contained one candidate with `role: "model"` and PNG
data. Always treat the returned `mimeType` as authoritative.