Seedream 5.0 Flash

Seedream 5.0 Flash is ByteDance’s faster, lower-cost model for image generation and editing. Use model ID doubao-seedream-5-0-flash-260915 with AnyFast’s POST /v1/images/generations endpoint. The upstream model supports text-to-image generation, single- and multi-image editing, transparent-background editing, and layer decomposition.

Seedream 5.0 Flash generates one image per normal generation request. It does not support grouped image generation, web search, or streaming. Do not send sequential_image_generation, sequential_image_generation_options, tools, or stream.

Key capabilities

Text to image — Generate one image from a text prompt
Image editing and fusion — Edit one reference or combine content and style from up to 10 references
Interactive editing — Point to regions with natural language, markers, points, bounding boxes, arrows, or sketches
Transparent background — Preserve an alpha channel in a single-image editing workflow
Layer decomposition — Split one image into a background plus up to 16 editable transparent PNG layers
Multilingual text — In addition to Chinese and English, supports Russian, Arabic, Filipino, Thai, Turkish, Korean, Malay, Spanish, Portuguese, Indonesian, French, German, Vietnamese, and Japanese prompts

Text to image
Image editing
Transparent background
Layer decomposition

Generate from text

curl https://www.anyfast.ai/v1/images/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "doubao-seedream-5-0-flash-260915",
    "prompt": "A premium product photograph of a white ceramic cup on a light gray background, centered composition, soft shadow, no text",
    "size": "1.5K",
    "response_format": "url",
    "output_format": "jpeg",
    "watermark": false
  }'

import requests

response = requests.post(
    "https://www.anyfast.ai/v1/images/generations",
    headers={
        "Authorization": "Bearer YOUR_API_KEY",
        "Content-Type": "application/json",
    },
    json={
        "model": "doubao-seedream-5-0-flash-260915",
        "prompt": "A premium product photograph of a white ceramic cup on a light gray background, centered composition, soft shadow, no text",
        "size": "1.5K",
        "response_format": "url",
        "output_format": "jpeg",
        "watermark": False,
    },
)

print(response.json())

size accepts 1K, 1.5K, 2K, or a valid explicit widthxheight value. Flash supports only standard prompt optimization; do not send optimize_prompt_options.mode: "fast".

Edit or combine references

cURL

curl https://www.anyfast.ai/v1/images/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "doubao-seedream-5-0-flash-260915",
    "prompt": "Use the composition of image 1 and the visual style of image 2.",
    "image": [
      "https://example.com/composition.png",
      "https://example.com/style.png"
    ],
    "size": "1K",
    "output_format": "jpeg",
    "watermark": false
  }'

image accepts a URL, a Base64 data URI, or an array of up to 10 references. In the prompt, refer to images by their array order, such as “image 1” and “image 2.”For coordinate-based editing, use coordinates in a 1000 × 1000 normalized coordinate system:

Coordinate-based edit

{
  "model": "doubao-seedream-5-0-flash-260915",
  "prompt": "Place the subject from image 1 <bbox>179 283 796 986</bbox> into image 2 <bbox>118 331 933 871</bbox>.",
  "image": [
    "https://example.com/source.png",
    "https://example.com/target.png"
  ],
  "size": "2K",
  "output_format": "png"
}

Preserve transparency

cURL

curl https://www.anyfast.ai/v1/images/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "doubao-seedream-5-0-flash-260915",
    "prompt": "Keep the subject and refine the edges while preserving the transparent background.",
    "image": "https://example.com/transparent-source.png",
    "background": "transparent",
    "size": "1K",
    "output_format": "png",
    "watermark": false
  }'

Transparent mode is available only for image-to-image requests with exactly one input image that already has an alpha channel. Use output_format: "png"; JPEG input or output is not compatible with transparency.

Split an image into layers

cURL

curl https://www.anyfast.ai/v1/images/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "doubao-seedream-5-0-flash-260915",
    "prompt": "Separate the green leaf icon from the white background into one editable layer.",
    "image": "https://example.com/green-leaf.jpeg",
    "layer_decomposition": true,
    "size": "1K",
    "response_format": "url",
    "output_format": "jpeg",
    "watermark": false
  }'

Layer decomposition accepts exactly one PNG or JPEG. It returns one background image and up to 16 transparent PNG layers. The background follows output_format; every extracted layer is PNG and includes z_index, bounding_box, name, and description metadata.

Response shape

{
  "model": "dola-seedream-5-0-flash-260915",
  "created": 1792129605,
  "data": [
    {
      "url": "https://example.com/seedream-flash-layer-0.jpeg",
      "size": "1024x1024",
      "output_format": "jpeg",
      "z_index": 0
    },
    {
      "url": "https://example.com/seedream-flash-layer-1.png",
      "size": "662x855",
      "output_format": "png",
      "z_index": 1,
      "bounding_box": {
        "absolute": [
          305,
          251,
          729,
          800
        ],
        "normalized": [
          298,
          245,
          711,
          780
        ]
      },
      "name": "green leaf icon",
      "description": "Extract the complete green leaf icon with leaf blade, veins and petiole, no other background elements included"
    }
  ],
  "usage": {
    "input_images": 1,
    "generated_images": 2,
    "output_tokens": 8549,
    "total_tokens": 8549
  }
}

For decomposition, size accepts auto, 1K, 1.5K, or 2K; explicit pixel sizes are not supported. If any requested layer fails, the whole request fails.

Output controls

Parameter	Values	Notes
`size`	`1K`, `1.5K`, `2K`, or explicit pixels	Normal generation defaults to `2K`; layer decomposition also supports `auto`
`response_format`	`url`, `b64_json`	URLs are valid for 24 hours; save them promptly
`output_format`	`jpeg`, `png`	Defaults to `jpeg`; transparent output and extracted layers use PNG
`background`	`opaque`, `transparent`	`transparent` is restricted to the single transparent-input workflow
`watermark`	`true`, `false`	Defaults to `true`
`optimize_prompt_options.mode`	`standard`	Default. Flash does not support `fast` mode.

Size and input limits

For normal generation, explicit dimensions must contain between 921,600 and 4,624,220 total pixels and use an aspect ratio in [1/16, 16]. Representative sizes include 1024x1024 for 1K, 1536x1536 for 1.5K, and 2048x2048 for 2K. Normal reference images support jpeg, png, webp, bmp, tiff, gif, heic, and heif. Each image must be smaller than 30 MB, have an aspect ratio in [1/16, 16], have width and height greater than 14 px, and contain from 196 through 36,000,000 pixels. Layer decomposition accepts one PNG or JPEG with 512×512 to 6000×6000 total pixels, with the same aspect-ratio and 30 MB limits.

API Reference

View all Seedream 5.0 Flash workflows.

​Key capabilities

​Generate from text

​Edit or combine references

​Preserve transparency

​Split an image into layers

​Output controls

​Size and input limits

API Reference

​Official references

Key capabilities

Generate from text

Edit or combine references

Preserve transparency

Split an image into layers

Output controls

Size and input limits

Official references