Stable Diffusion 3.5 Large

Stability AI's highest-quality SD 3.5 model for detailed, photorealistic images.

POST /v2/images/generate — model: "stable-diffusion-3.5-large"

The largest and highest-quality Stable Diffusion 3.5 model. An 8-billion-parameter MMDiT model with excellent prompt adherence, typography, and image quality. Supports image-to-image via the image parameter.

See Image Generation overview for common request fields, response format, and error codes.

Model-specific parameters

Parameter	Type	Description
`stableDiffusionParams.aspect_ratio`	string	Output aspect ratio. Values: `"1:1"`, `"16:9"`, `"21:9"`, `"3:2"`, `"2:3"`, `"4:5"`, `"5:4"`, `"9:16"`, `"9:21"`. Ignored when `image` is set
`stableDiffusionParams.cfg`	number	Guidance scale (0–20). How strictly to follow the prompt. Default `3.5`
`stableDiffusionParams.steps`	integer	Number of sampling steps (1–40). Default `28`
`stableDiffusionParams.seed`	integer	Random seed for reproducible generation
`stableDiffusionParams.negative_prompt`	string	What you do NOT want to see in the image
`stableDiffusionParams.image`	string	Input image URL for image-to-image mode. Output aspect ratio matches this image
`stableDiffusionParams.prompt_strength`	number	Denoising strength for image-to-image (0–1). `1.0` fully replaces the input image. Default `0.85`
`stableDiffusionParams.output_format`	string	Output image format. Values: `"webp"`, `"jpg"`, `"png"`. Default `"webp"`
`stableDiffusionParams.output_quality`	integer	Output quality for lossy formats (0–100). Default `90`

Credit cost

Credits per generation
12

Example result

Once the job is COMPLETED, the result object on GET /v2/jobs/:id looks like:

{
  "images": [
    "https://cdn2.apiframe.ai/images/a1b2c3d4-e5f6-7890-abcd-ef1234567890-1.png"
  ]
}

See Result format for field details.

Code examples

curl -X POST https://api.apiframe.ai/v2/images/generate \
  -H "X-API-Key: afk_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A photorealistic portrait of an astronaut in a field of wildflowers",
    "model": "stable-diffusion-3.5-large",
    "stableDiffusionParams": {
      "aspect_ratio": "1:1",
      "cfg": 3.5,
      "steps": 28
    }
  }'

import requests

response = requests.post(
    "https://api.apiframe.ai/v2/images/generate",
    headers={
        "X-API-Key": "afk_your_api_key_here",
        "Content-Type": "application/json",
    },
    json={
        "prompt": "A photorealistic portrait of an astronaut in a field of wildflowers",
        "model": "stable-diffusion-3.5-large",
        "stableDiffusionParams": {
            "aspect_ratio": "1:1",
            "cfg": 3.5,
            "steps": 28,
        },
    },
)
print(response.json())

const response = await fetch("https://api.apiframe.ai/v2/images/generate", {
  method: "POST",
  headers: {
    "X-API-Key": "afk_your_api_key_here",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    prompt: "A photorealistic portrait of an astronaut in a field of wildflowers",
    model: "stable-diffusion-3.5-large",
    stableDiffusionParams: { aspect_ratio: "1:1", cfg: 3.5, steps: 28 },
  }),
});
console.log(await response.json());

Try it

POST/v2/images/generateTry it

API Key

Request Body (JSON)