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Flux Schnell is Black Forest Labs’ fastest and most lightweight FLUX model, ideal for local development, prototyping, and personal use. It generates images quickly with lower step counts while maintaining good quality.

Try in playground

Test Flux Schnell in the Runpod Hub playground.
Endpointhttps://api.runpod.ai/v2/black-forest-labs-flux-1-schnell/runsync
Pricing$0.0024 per megapixel
TypeImage generation
Flux Schnell is optimized for speed and works best with lower step counts. For higher fidelity production images, consider Flux Dev.

​
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:"4"
Number of denoising steps. Schnell is optimized for low step counts. Range: 1-8.
​
input.guidance
float
default:"7.5"
How closely to follow the prompt. Higher values produce images more faithful to the prompt. 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-schnell/runsync" \
  -H "Authorization: Bearer $RUNPOD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": {
      "prompt": "A quick sketch of a mountain landscape",
      "width": 1024,
      "height": 1024,
      "num_inference_steps": 4,
      "guidance": 1.0,
      "seed": 123
    }
  }'

import requests

response = requests.post(
    "https://api.runpod.ai/v2/black-forest-labs-flux-1-schnell/runsync",
    headers={
        "Authorization": f"Bearer {RUNPOD_API_KEY}",
        "Content-Type": "application/json",
    },
    json={
        "input": {
            "prompt": "A quick sketch of a mountain landscape",
            "width": 1024,
            "height": 1024,
            "num_inference_steps": 4,
            "guidance": 1.0,
            "seed": 123,
        }
    },
)

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

const response = await fetch(
  "https://api.runpod.ai/v2/black-forest-labs-flux-1-schnell/runsync",
  {
    method: "POST",
    headers: {
      Authorization: `Bearer ${RUNPOD_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      input: {
        prompt: "A quick sketch of a mountain landscape",
        width: 1024,
        height: 1024,
        num_inference_steps: 4,
        guidance: 1.0,
        seed: 123,
      },
    }),
  }
);

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": 12,
  "executionTime": 856,
  "workerId": "oqk7ao1uomckye",
  "output": {
    "image_url": "https://image.runpod.ai/abc123/output.png",
    "cost": 0.00251658
  }
}

{
  "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 Schnell charges $0.0024 per megapixel. Cost is calculated as: (width × height / 1,000,000) × \$0.0024.
Image sizeMegapixelsCost
512×5120.26 MP$0.0006
1024×10241.05 MP$0.0025
1536×15362.36 MP$0.0057