black-forest-labs

flux-schnell

Warm

The fastest image generation model tailored for local development and personal use

Official

435.9M runs

$3 per thousand output images

Commercial use

Blog post: Learn about training with Flux Read the blog

Run with an API

Playground API Examples README

Input

prompt

*string

Shift + Return to add a new line

black forest gateau cake spelling out the words "FLUX SCHNELL", tasty, food photography, dynamic shotblack forest gateau cake spelling out the words "FLUX SCHNELL", tasty, food photography, dynamic shot

Prompt for generated image

aspect_ratio

string

Aspect ratio for the generated image

Default: "1:1"

num_outputs

integer

(minimum: 1, maximum: 4)

Number of outputs to generate

Default: 1

num_inference_steps

integer

(minimum: 1, maximum: 4)

Number of denoising steps. 4 is recommended, and lower number of steps produce lower quality outputs, faster.

Default: 4

seed

integer

Random seed. Set for reproducible generation

output_format

string

Format of the output images

Default: "webp"

output_quality

integer

(minimum: 0, maximum: 100)

Quality when saving the output images, from 0 to 100. 100 is best quality, 0 is lowest quality. Not relevant for .png outputs

Default: 80

disable_safety_checker

boolean

Disable safety checker for generated images.

Default: false

go_fast

boolean

Run faster predictions with model optimized for speed (currently fp8 quantized); disable to run in original bf16. Note that outputs will not be deterministic when this is enabled, even if you set a seed.

Default: true

megapixels

string

Approximate number of megapixels for generated image

Default: "1"

Run this model in Node.js with one line of code:

npx create-replicate --model=black-forest-labs/flux-schnell

or set up a project from scratch

Install Replicate’s Node.js client library:

npm install replicate

Set the REPLICATE_API_TOKEN environment variable:

export REPLICATE_API_TOKEN=<paste-your-token-here>

Find your API token in your account settings.

Import and set up the client:

import Replicate from "replicate";
import fs from "node:fs";

const replicate = new Replicate({
  auth: process.env.REPLICATE_API_TOKEN,
});

Run black-forest-labs/flux-schnell using Replicate’s API. Check out the model's schema for an overview of inputs and outputs.

const input = {
  prompt: "black forest gateau cake spelling out the words \"FLUX SCHNELL\", tasty, food photography, dynamic shot",
  go_fast: true,
  megapixels: "1",
  num_outputs: 1,
  aspect_ratio: "1:1",
  output_format: "webp",
  output_quality: 80,
  num_inference_steps: 4
};

const output = await replicate.run("black-forest-labs/flux-schnell", { input });

// To access the file URL:
console.log(output[0].url()); //=> "http://example.com"

// To write the file to disk:
fs.writeFile("my-image.png", output[0]);

To learn more, take a look at the guide on getting started with Node.js.

Install Replicate’s Python client library:

pip install replicate

Set the REPLICATE_API_TOKEN environment variable:

export REPLICATE_API_TOKEN=<paste-your-token-here>

Find your API token in your account settings.

Import the client:

import replicate

Run black-forest-labs/flux-schnell using Replicate’s API. Check out the model's schema for an overview of inputs and outputs.

output = replicate.run(
    "black-forest-labs/flux-schnell",
    input={
        "prompt": "black forest gateau cake spelling out the words \"FLUX SCHNELL\", tasty, food photography, dynamic shot",
        "go_fast": True,
        "megapixels": "1",
        "num_outputs": 1,
        "aspect_ratio": "1:1",
        "output_format": "webp",
        "output_quality": 80,
        "num_inference_steps": 4
    }
)

# To access the file URL:
print(output[0].url())
#=> "http://example.com"

# To write the file to disk:
with open("my-image.png", "wb") as file:
    file.write(output[0].read())

To learn more, take a look at the guide on getting started with Python.

Set the REPLICATE_API_TOKEN environment variable:

export REPLICATE_API_TOKEN=<paste-your-token-here>

Find your API token in your account settings.

Run black-forest-labs/flux-schnell using Replicate’s API. Check out the model's schema for an overview of inputs and outputs.

curl -s -X POST \
  -H "Authorization: Bearer $REPLICATE_API_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Prefer: wait" \
  -d $'{
    "input": {
      "prompt": "black forest gateau cake spelling out the words \\"FLUX SCHNELL\\", tasty, food photography, dynamic shot",
      "go_fast": true,
      "megapixels": "1",
      "num_outputs": 1,
      "aspect_ratio": "1:1",
      "output_format": "webp",
      "output_quality": 80,
      "num_inference_steps": 4
    }
  }' \
  https://api.replicate.com/v1/models/black-forest-labs/flux-schnell/predictions

To learn more, take a look at Replicate’s HTTP API reference docs.

Output

Generated in

0.8 seconds

Tweak it Iterate in playground Share Report View full prediction

Examples

View more examples

Pricing

Model pricing for black-forest-labs/flux-schnell. Looking for volume pricing? Get in touch.

per thousand output images

or around 333 images for $1

Official models are always on, maintained, and have predictable pricing. Learn more.

Check out our docs for more information about how pricing works on Replicate.

Readme

FLUX.1 [schnell] is a 12 billion parameter rectified flow transformer capable of generating images from text descriptions. For more information, please read our blog post.

Key Features

Cutting-edge output quality and competitive prompt following, matching the performance of closed source alternatives.
Trained using latent adversarial diffusion distillation, FLUX.1 [schnell] can generate high-quality images in only 1 to 4 steps.
Released under the apache-2.0 licence, the model can be used for personal, scientific, and commercial purposes.

Usage

We provide a reference implementation of FLUX.1 [schnell], as well as sampling code, in a dedicated github repository. Developers and creatives looking to build on top of FLUX.1 [schnell] are encouraged to use this as a starting point.

ComfyUI

FLUX.1 [schnell] is also available in Comfy UI for local inference with a node-based workflow.

Limitations

This model is not intended or able to provide factual information.
As a statistical model this checkpoint might amplify existing societal biases.
The model may fail to generate output that matches the prompts.
Prompt following is heavily influenced by the prompting-style.

Out-of-Scope Use

The model and its derivatives may not be used

In any way that violates any applicable national, federal, state, local or international law or regulation.
For the purpose of exploiting, harming or attempting to exploit or harm minors in any way; including but not limited to the solicitation, creation, acquisition, or dissemination of child exploitative content.
To generate or disseminate verifiably false information and/or content with the purpose of harming others.
To generate or disseminate personal identifiable information that can be used to harm an individual.
To harass, abuse, threaten, stalk, or bully individuals or groups of individuals.
To create non-consensual nudity or illegal pornographic content.
For fully automated decision making that adversely impacts an individual’s legal rights or otherwise creates or modifies a binding, enforceable obligation.
Generating or facilitating large-scale disinformation campaigns.

Accelerated Inference

We provide a go_fast flag within the API which toggles a version of flux-schnell optimized for inference. Currently this version is a compiled fp8 quantization with an optimized attention kernel. We’ll update the model and this documentation as we develop further enhancements.