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

# Multimodal input

> Send images and other supported inputs with size, format, and privacy controls.

Multimodal input structure depends on the protocol and model. Query model parameters first to confirm supported input types, image count, size, format, and delivery method.

## OpenAI-compatible image example

```json theme={null}
{
  "model": "YOUR_VISION_MODEL_ID",
  "messages": [
    {
      "role": "user",
      "content": [
        {"type": "text", "text": "Summarize the main information in the image"},
        {"type": "image_url", "image_url": {"url": "https://example.com/image.png"}}
      ]
    }
  ]
}
```

This is a common OpenAI-compatible structure. Anthropic and Gemini use different content blocks; do not copy request bodies across protocols directly.

## URL, Base64, and file references

| Method | Advantage | Considerations |
| - | - | - |
| HTTPS URL | Small request body | URL must be reachable by the service; avoid long-term public exposure of sensitive files |
| Base64 / Data URL | No external download dependency | Request body increases significantly; watch size limits and log leakage |
| File ID or upload interface | Easy to reuse | Only use when explicitly supported by the model or platform |

## Input preprocessing

* Remove EXIF, location, and unnecessary personal information.
* Scale oversized images to the resolution required by your application.
* Verify MIME type matches the actual file type.
* Prepare test samples for scanned documents, tables, and screenshots separately.
* Do not log full Base64 or temporary signed URLs.

## Common errors

| Symptom | Check |
| - | - |
| Model does not recognize the image | Whether the model supports vision, and whether the protocol structure is correct |
| URL download fails | Whether it is publicly reachable, expired, or blocking server access |
| 413 | Image count, resolution, or Base64 body size too large |
| Response ignores an image | Image order, text instructions, and model image count limits |
| Unstable OCR | Image clarity, rotation, language, and layout complexity |

Next: [Model selection](https://apione.ai/docs/en/models/selection.md), [Structured output](https://apione.ai/docs/en/api/structured-output.md), [Image generation](https://apione.ai/docs/en/api/images-generations.md), [Request reliability](https://apione.ai/docs/en/api/request-reliability.md).


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