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Endpoint https://fal.run/fal-ai/flux-1/dev
Model ID fal-ai/flux-1/dev
Category Text-to-image · inference
Tags
flow transformer commercial use fast

Interactive Playground

Configure prompts, sampling settings, and acceleration tiers, then call the fal.ai endpoint directly from your browser.

Default 28 · 1 to 50 steps

Range 1-20 · higher = tighter prompt adherence

Default 1 · up to 4 images

Higher tiers trade cost for speed

{}

Status

Idle

Response

Waiting for first request...

Generated Images

Input Schema

prompt (string, required)

The text description that drives the render.

image_size (enum | object)

Tokens like landscape_4_3 or a custom object: { width, height }.

num_inference_steps (integer)

How many diffusion steps to run. Default 28.

seed (integer)

Repeat inputs to recreate the same image.

guidance_scale (float)

CFG strength: 1-20, default 3.5.

sync_mode (boolean)

Return data URI inline (no request history) when true.

num_images (integer)

Number of outputs per request. Range 1-4.

enable_safety_checker (boolean)

Default true. Disable at your own risk.

output_format (enum)

jpeg (default) or png.

acceleration (enum)

Select none, regular, or high to change throughput.

Output Schema

images

Array of { url, content_type } objects.

timings

Queue + generation duration metrics.

seed

The seed echo for reproducibility.

has_nsfw_concepts

Boolean array reporting NSFW detections.

prompt

The prompt that generated the output.

Usage Examples

cURL
curl --request POST \
  --url https://fal.run/fal-ai/flux-1/dev \
  --header "Authorization: Key $FAL_KEY" \
  --header "Content-Type: application/json" \
  --data '{
    "prompt": "Extreme close-up of a single tiger eye, direct frontal view. Detailed iris and pupil. Sharp focus on eye texture and color. Natural lighting to capture authentic eye shine and depth. The word \"FLUX\" is painted over it in big, white brush strokes with visible texture."
  }'
Python
import fal_client

def on_queue_update(update):
    if isinstance(update, fal_client.InProgress):
        for log in update.logs:
            print(log["message"])

result = fal_client.subscribe(
    "fal-ai/flux-1/dev",
    arguments={
        "prompt": "Extreme close-up of a single tiger eye..."
    },
    with_logs=True,
    on_queue_update=on_queue_update,
)
print(result)
JavaScript
import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/flux-1/dev", {
  input: {
    prompt: "Extreme close-up of a single tiger eye..."
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);

Additional Resources