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Flux Dev is Black Forest Labs’ flagship image generation model, optimized for high visual fidelity and detailed outputs. It offers exceptional prompt adherence and produces images with rich detail, making it ideal for production use cases.

Try in playground

Test Flux Dev in the Runpod Hub playground.
Endpointhttps://api.runpod.ai/v2/black-forest-labs-flux-1-dev/runsync
Pricing$0.02 per megapixel
TypeImage generation
For faster, cheaper generation during development, consider Flux Schnell which is optimized for speed.

​
Request

All parameters are passed within the input object in the request body.
​
input.prompt
string
required
Text description of the desired image. Be specific and detailed for best results.
​
input.negative_prompt
string
Elements to exclude from the generated image. Use this to prevent unwanted features or styles.
​
input.width
integer
default:"1024"
Image width in pixels. Must be divisible by 64. Range: 256-1536.
​
input.height
integer
default:"1024"
Image height in pixels. Must be divisible by 64. Range: 256-1536.
​
input.num_inference_steps
integer
default:"28"
Number of denoising steps. Higher values produce more detailed images but take longer. Range: 1-50.
​
input.guidance
float
default:"7.5"
How closely to follow the prompt. Higher values produce images more faithful to the prompt but may reduce creativity. Range: 0.0-10.0.
​
input.seed
integer
default:"-1"
Seed for reproducible results. Use the same seed with identical parameters to generate the same image. Set to -1 for random.
​
input.image_format
string
default:"jpeg"
Output image format. Accepts png or jpeg.
curl -X POST "https://api.runpod.ai/v2/black-forest-labs-flux-1-dev/runsync" \
  -H "Authorization: Bearer $RUNPOD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": {
      "prompt": "A serene mountain landscape at sunset, golden light filtering through clouds, photorealistic",
      "negative_prompt": "blurry, low quality",
      "width": 1024,
      "height": 1024,
      "num_inference_steps": 28,
      "guidance": 7.5,
      "seed": 42,
      "image_format": "png"
    }
  }'

import requests

response = requests.post(
    "https://api.runpod.ai/v2/black-forest-labs-flux-1-dev/runsync",
    headers={
        "Authorization": f"Bearer {RUNPOD_API_KEY}",
        "Content-Type": "application/json",
    },
    json={
        "input": {
            "prompt": "A serene mountain landscape at sunset, golden light filtering through clouds, photorealistic",
            "negative_prompt": "blurry, low quality",
            "width": 1024,
            "height": 1024,
            "num_inference_steps": 28,
            "guidance": 7.5,
            "seed": 42,
            "image_format": "png",
        }
    },
)

result = response.json()
print(result["output"]["image_url"])

const response = await fetch(
  "https://api.runpod.ai/v2/black-forest-labs-flux-1-dev/runsync",
  {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${RUNPOD_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      input: {
        prompt: "A serene mountain landscape at sunset, golden light filtering through clouds, photorealistic",
        negative_prompt: "blurry, low quality",
        width: 1024,
        height: 1024,
        num_inference_steps: 28,
        guidance: 7.5,
        seed: 42,
        image_format: "png",
      },
    }),
  }
);

const result = await response.json();
console.log(result.output.image_url);

​
Response

​
id
string
Unique identifier for the request.
​
status
string
Request status. Returns COMPLETED on success, FAILED on error.
​
delayTime
integer
Time in milliseconds the request spent in queue before processing began.
​
executionTime
integer
Time in milliseconds the model took to generate the image.
​
workerId
string
Identifier of the worker that processed the request.
​
output
object
The generation result containing the image URL and cost.
​
output.image_url
string
URL of the generated image. This URL expires after 7 days.
​
output.cost
float
Cost of the generation in USD, calculated based on the output megapixels.
{
  "id": "sync-a1b2c3d4-e5f6-7890-abcd-ef1234567890-u1",
  "status": "COMPLETED",
  "delayTime": 17,
  "executionTime": 3986,
  "workerId": "oqk7ao1uomckye",
  "output": {
    "image_url": "https://image.runpod.ai/abc123/output.png",
    "cost": 0.02097152
  }
}

{
  "id": "sync-a1b2c3d4-e5f6-7890-abcd-ef1234567890-u1",
  "status": "FAILED",
  "error": "Invalid parameter: width must be divisible by 64"
}
Image URLs expire after 7 days. Download and store generated images immediately if you need to keep them.

​
Cost calculation

Flux Dev charges $0.02 per megapixel. Cost is calculated as: (width × height / 1,000,000) × \$0.02.
Image sizeMegapixelsCost
512×5120.26 MP$0.0052
1024×10241.05 MP$0.021
1536×15362.36 MP$0.047