# FLUX1.1 [pro]

> Black Forest Labs' enhanced 12-billion parameter flow transformer with 6x faster generation than FLUX.1 [pro], delivering superior composition, detail, and artistic fidelity

## Quick Reference

- Model ID: flux1.1-pro
- Creator: Black Forest Labs
- Status: active
- Family: flux1.1
- Base URL: https://api.lumenfall.ai/openai/v1

## Specifications

- Max Resolution: 2048x2048
- Input Modalities: text
- Output Modalities: image
- Supported Modes: Text to Image

## API Parameters

The compiled parameter schema for this model is available via the API: `GET /v1/models/flux1.1-pro?schema=true`.

### Core Parameters

- `prompt` (string) — REQUIRED: Text prompt for image generation
- `seed` (integer): Random seed for reproducibility

### Size & Layout

- `size` (string): Image dimensions as WxH pixels (e.g. "1024x1024") or aspect ratio (e.g. "16:9"). Values: 1365x768, 768x1365, 1254x836, 836x1254, 887x1182, 1024x1024, 1145x916, 916x1145, 1183x887
- `aspect_ratio` (string): Aspect ratio of the output image (e.g. "16:9", "1:1"). Values: 9:16, 2:3, 3:4, 4:5, 1:1, 5:4, 4:3, 3:2, 16:9
- `resolution` (string): Output resolution tier (e.g. "1K", "4K"). Values: 1K

### Output & Format

- `response_format` (string): How to return the image. Default: url. Values: url, b64_json
- `output_format` (string): Output image format. Values: png, jpeg, gif, webp, avif
- `output_compression` (integer): Compression level for lossy formats (JPEG, WebP, AVIF)
- `n` (integer): Number of images to generate. Default: 1

### Additional Parameters

- `enhance_prompt` (boolean): Whether to enhance the prompt for better results.. Only available via fal
- `height` (integer): Height of the generated image in text-to-image mode. Only used when aspect_ratio=custom. Must be a multiple of 32 (if it's not, it will be rounded to nearest multiple of 32). Note: Ignored in img2img and inpainting modes.. Only available via replicate
- `image_prompt` (string): Image to use with Flux Redux. This is used together with the text prompt to guide the generation towards the composition of the image_prompt. Must be jpeg, png, gif, or webp.. Only available via replicate
- `output_quality` (integer): Quality when saving the output images, from 0 to 100. 100 is best quality, 0 is lowest quality. Not relevant for .png outputs. Only available via replicate
- `prompt_upsampling` (boolean): Automatically modify the prompt for more creative generation. Only available via replicate
- `safety_tolerance` (string): The safety tolerance level for the generated image. 1 being the most strict and 5 being the most permissive.. Values: 1, 2, 3, 4, 5, 6
- `sync_mode` (boolean): If `True`, the media will be returned as a data URI and the output data won't be available in the request history.. Only available via fal
- `width` (integer): Width of the generated image in text-to-image mode. Only used when aspect_ratio=custom. Must be a multiple of 32 (if it's not, it will be rounded to nearest multiple of 32). Note: Ignored in img2img and inpainting modes.. Only available via replicate


## Model Identifiers

- Primary Slug: flux1.1-pro
- Aliases: flux-pro-1.1


## Tags

image-generation, text-to-image, photorealistic, fast

## Available Providers

### fal.ai

- Config Key: fal/flux1.1-pro
- Provider Model ID: fal-ai/flux-pro/v1.1
- Pricing: $0.040/image
  - Source: https://fal.ai/models/fal-ai/flux-pro/v1.1

### Replicate

- Config Key: replicate/flux1.1-pro
- Provider Model ID: black-forest-labs/flux-1.1-pro
- Pricing: $0.040/image
  - Source: https://replicate.com/black-forest-labs/flux-1.1-pro


## Image Gallery

4 images available for this model. Browse all at https://lumenfall.ai/models/black-forest-labs/flux1.1-pro/gallery

### Curated Examples

- [A wide, cinematic shot of a sophisticated high-end camera lens boutique at dusk; the shop’s charc...](https://assets.lumenfall.ai/ftgElmC-g2AMb5sKStPJWVhfN92hn-olJkoPtQuoqM0/rs:fit:1500:1500/plain/gs://lumenfall-prod-assets/b8gbhv8fhyala7gq2oxqtfjkhoeq@jpeg)
- [A medium-shot hyper-realistic portrait of an elderly watchmaker in a sun-drenched, dusty workshop...](https://assets.lumenfall.ai/ff8oUKi-T53bBZvaLfL27kHUm0UtKKBWntS6yn5Pqt4/rs:fit:1500:1500/plain/gs://lumenfall-prod-assets/cwrx54j0qjju0fab89jo86nabyy2@jpeg)
- [A hyper-realistic close-up portrait of an elderly watchmaker in a sun-drenched workshop, focusing...](https://assets.lumenfall.ai/0O3Dl0ohFXMJJDGAMyJmqcf_dyzNNXa6sJTITOKHFRM/rs:fit:1500:1500/plain/gs://lumenfall-prod-assets/5gnsxwpnaeroyhyfeecb0i40bqx4@jpeg)
- [A vibrant chalkboard outside a cozy Parisian bakery, displaying the text "FRESH CROISSANTS & COFF...](https://assets.lumenfall.ai/31jjlV5d1VKzZfO9YcWZQBoTFCVO5EtLm3H6fG9K064/rs:fit:1500:1500/plain/gs://lumenfall-prod-assets/fw7qc2xnxxfh2dmbqzy8yrhzb7d4@jpeg)

## Example Prompt

The following prompt was used to generate an example image in our playground:

A vibrant chalkboard outside a cozy Parisian bakery, displaying the text "FRESH CROISSANTS & COFFEE" in elegant hand-drawn cursive. In the blurred background, a capybara calmly sits on a cafe chair, wearing a tiny beret. Photorealistic, 8k.

## Code Examples

### Text to Image (/v1/images/generations)

#### cURL

curl -X POST \
  https://api.lumenfall.ai/openai/v1/images/generations \
  -H "Authorization: Bearer $LUMENFALL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "flux1.1-pro",
    "prompt": "",
    "size": "1024x1024"
  }'

# Response:
# { "created": 1234567890, "data": [{ "url": "https://...", "revised_prompt": "..." }] }

#### JavaScript

import OpenAI from 'openai';

const client = new OpenAI({
  apiKey: 'YOUR_API_KEY',
  baseURL: 'https://api.lumenfall.ai/openai/v1'
});

const response = await client.images.generate({
  model: 'flux1.1-pro',
  prompt: '',
  size: '1024x1024'
});

// { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }
console.log(response.data[0].url);

#### Python

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://api.lumenfall.ai/openai/v1"
)

response = client.images.generate(
    model="flux1.1-pro",
    prompt="",
    size="1024x1024"
)

# { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }
print(response.data[0].url)


## About

## Overview
FLUX1.1 [pro] is a high-performance text-to-image model developed by Black Forest Labs, designed to balance elite output quality with rapid generation speeds. It is an evolution of the FLUX.1 architecture, utilizing a 12-billion parameter flow transformer to produce high-resolution imagery six times faster than its predecessor. This model is engineered for professional workflows that require high-fidelity details, precise prompt adherence, and efficient batch processing.

## Strengths
*   **Generation Velocity:** Provides a 6x speed increase over the original FLUX.1 [pro], significantly reducing latency for high-resolution image synthesis.
*   **Instruction Adherence:** Excels at interpreting complex, multi-subject prompts with high spatial accuracy and compositional integrity.
*   **Anatomical and Textual Accuracy:** Demonstrates superior rendering of fine details, including realistic human anatomy (particularly hands) and legible, coherent text within generated images.
*   **Artistic Versatility:** Balances photorealistic output with the ability to execute various aesthetic styles, from cinematic photography to digital illustration, without losing detail.

## Limitations
*   **Hardware and Cost Requirements:** As a "pro" tier model with 12 billion parameters, it requires substantial computational resources and carries a higher cost per generation ($0.04) compared to smaller "schnell" or "dev" variants.
*   **Fixed Modality:** The model is currently focused strictly on text-to-image generation and does not natively support multi-modal inputs like image-to-image or video out-of-the-box without specialized pipeline implementations.

## Technical Background
FLUX1.1 [pro] is built on a "flow transformer" architecture, a design that optimizes the diffusion process by modeling the straight-line paths between data and noise. This iteration focuses on refined sampling efficiency, allowing the model to reach high-convergence states in fewer steps than traditional diffusion models. The training emphasizes high-parameter density to capture intricate textures and global scene coherence.

## Best For
FLUX1.1 [pro] is ideal for commercial design projects, advertising assets, and any professional application where speed-to-market and visual precision are critical. It is particularly effective for generating marketing copy embedded in imagery or high-fidelity character concept art. Developers can access FLUX1.1 [pro] through Lumenfall’s unified API and interactive playground, enabling rapid testing and integration into production-ready creative pipelines.

## Frequently Asked Questions

### How much does FLUX1.1 [pro] cost?

FLUX1.1 [pro] starts at $0.04 per image through Lumenfall. Pricing varies by provider. Lumenfall does not add any markup to provider pricing.

### How do I use FLUX1.1 [pro] via API?

You can use FLUX1.1 [pro] through Lumenfall's OpenAI-compatible API. Send requests to the unified endpoint with model ID "flux1.1-pro". Code examples are available in Python, JavaScript, and cURL.

### Which providers offer FLUX1.1 [pro]?

FLUX1.1 [pro] is available through fal.ai and Replicate on Lumenfall. Lumenfall automatically routes requests to the best available provider.

### What is the maximum resolution for FLUX1.1 [pro]?

FLUX1.1 [pro] supports images up to 2048x2048 resolution.

## Links

- Model Page: https://lumenfall.ai/models/black-forest-labs/flux1.1-pro
- About: https://lumenfall.ai/models/black-forest-labs/flux1.1-pro/about
- Providers, Pricing & Performance: https://lumenfall.ai/models/black-forest-labs/flux1.1-pro/providers
- API Reference: https://lumenfall.ai/models/black-forest-labs/flux1.1-pro/api
- Benchmarks: https://lumenfall.ai/models/black-forest-labs/flux1.1-pro/benchmarks
- Use Cases: https://lumenfall.ai/models/black-forest-labs/flux1.1-pro/use-cases
- Gallery: https://lumenfall.ai/models/black-forest-labs/flux1.1-pro/gallery
- Playground: https://lumenfall.ai/playground?model=flux1.1-pro
- API Documentation: https://docs.lumenfall.ai