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

# Seedream 5.5 Pro

> Generate and edit images with Seedream 5.5 Pro, including transparent RGBA assets and consistent multi-turn edits.

Use Seedream 5.5 Pro through AnyFast for text-to-image generation, reference-image editing, and transparent image output. The request model ID is `seedream-5-5-pro`. ByteDance's Seedream 5.5 announcement describes the series' multi-turn editing, native RGBA, realism, and text-rendering capabilities.

> [!WARNING]
>
> To request transparent output, set `background` to `transparent` and `output_format` to `png`. A request without `background: "transparent"` returns an opaque image.

## Key capabilities

* **Text to image** — Create images from natural-language prompts with realistic textures and clear rendered text
* **Image editing** — Refine a reference image over multiple turns while preserving regions outside the requested edit
* **Transparent background** — Generate images with full or partial transparency in native RGBA output

> [tab] Text to image
>
> ## Generate from text
>
> ```bash cURL theme={null}
> curl https://www.anyfast.ai/v1/images/generations \
>   -H "Authorization: Bearer YOUR_API_KEY" \
>   -H "Content-Type: application/json" \
>   -d '{
>     "model": "seedream-5-5-pro",
>     "prompt": "A lifelike editorial photograph of a ceramic teapot on a wooden table, soft morning window light, fine glaze and wood textures",
>     "size": "1K",
>     "response_format": "url",
>     "output_format": "png",
>     "watermark": false
>   }'
> ```
>
> ```python Python theme={null}
> import requests
>
> response = requests.post(
>     "https://www.anyfast.ai/v1/images/generations",
>     headers={
>         "Authorization": "Bearer YOUR_API_KEY",
>         "Content-Type": "application/json",
>     },
>     json={
>         "model": "seedream-5-5-pro",
>         "prompt": "A lifelike editorial photograph of a ceramic teapot on a wooden table, soft morning window light, fine glaze and wood textures",
>         "size": "1K",
>         "response_format": "url",
>         "output_format": "png",
>         "watermark": False,
>     },
> )
>
> print(response.json())
> ```
>
> The Seedream 5.5 series is designed to render lighting, materials, and skin textures naturally and to improve text rendering. Describe the intended composition, materials, lighting, and any exact text in the prompt.

> [tab] Image editing
>
> ## Edit or refine a reference image
>
> ```bash cURL theme={null}
> curl https://www.anyfast.ai/v1/images/generations \
>   -H "Authorization: Bearer YOUR_API_KEY" \
>   -H "Content-Type: application/json" \
>   -d '{
>     "model": "seedream-5-5-pro",
>     "prompt": "Change the blue scarf to forest green. Preserve the subject, pose, background, lighting, and all other details.",
>     "image": "https://example.com/source-image.png",
>     "size": "1K",
>     "response_format": "url",
>     "output_format": "png",
>     "watermark": false
>   }'
> ```
>
> For multi-turn editing, pass the latest generated image as `image` in the next request. State which region or element to change and which details to preserve. ByteDance describes pixel-level preservation of unchanged regions across successive Seedream 5.5 edits.
>
> ![ByteDance demonstration of successive Seedream 5.5 edits while preserving the rest of an image](https://lf3-static.bytednsdoc.com/obj/eden-cn/bdeh7uhpsuht/sd55-e01c-82a14c50.gif)
>
> Official Seedream 5.5 multi-turn editing example (announcement model). Source: ByteDance Seed.

> [tab] Transparent background
>
> ## Generate a transparent image
>
> ```bash cURL theme={null}
> curl https://www.anyfast.ai/v1/images/generations \
>   -H "Authorization: Bearer YOUR_API_KEY" \
>   -H "Content-Type: application/json" \
>   -d '{
>     "model": "seedream-5-5-pro",
>     "prompt": "A detailed snowy owl in flight, isolated asset, transparent background outside the owl, preserve fine feather edges",
>     "size": "1K",
>     "response_format": "url",
>     "output_format": "png",
>     "background": "transparent",
>     "watermark": false
>   }'
> ```
>
> Seedream 5.5 supports full and partial transparency. Use PNG output to retain the alpha channel.
>
> ![ByteDance demonstration of image assets generated with transparent backgrounds](https://lf3-static.bytednsdoc.com/obj/eden-cn/bdeh7uhpsuht/sd55-r03zc-34532bd0.gif)
>
> Official Seedream 5.5 transparent-asset example (announcement model). Source: ByteDance Seed.

## Output controls

| Parameter | Values | Notes |
| - | - | - |
| `size` | `1K`, `1.5K`, `2K` | The response reports actual image dimensions in `data[].size`: `1K` returned `1248x832`, `1.5K` returned `1888x1248`, and `2K` returned `2512x1680`. |
| `response_format` | `url`, `b64_json` | Returns a temporary URL or Base64 image data. |
| `output_format` | `png`, `jpeg` | Both formats are accepted. Use PNG to preserve transparency. |
| `background` | `opaque`, `transparent` | Set to `transparent` to request RGBA output with transparency. |
| `watermark` | `true`, `false` | Controls whether to add an AI-generated watermark. |
| `image` | Image URL | Source image for an editing request. |

## Size and input limits

The `size` options `1K`, `1.5K`, and `2K` were accepted. Their returned dimensions were `1248x832`, `1888x1248`, and `2512x1680`, respectively. The response includes the actual dimensions in `data[].size`. For image editing, pass a source image URL in `image`.

See the [official Seedream 5.5 overview](https://seed.bytedance.com/en/seedream5_5) and [Seedream 5.5 announcement](https://seed.bytedance.com/en/blog/more-realistic-images-more-stable-editing-across-100-rounds-introducing-seedream-5-5) for model capabilities.

> [card] [API Reference](https://docs.anyfast.ai/api-reference/model-api/bytedance/seedream-5-5.md)
>
> View all Seedream 5.5 Pro workflows.


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