FLUX1.1 [pro] Ultra

Name: FLUX1.1 [pro] Ultra
Brand: Black Forest Labs
Price: 0.06 USD
Availability: InStock

AI Image Generation Model

Image

Black Forest Labs' ultra-high resolution image generation model, an enhanced version of FLUX1.1 [pro] optimized for premium quality output

Try Model

2048 x 2048

Max Resolution

Supported Modes

Text to Image

Active

Details

Model ID

flux1.1-pro-ultra

Also known as: flux-pro-1.1-ultra

Creator

Black Forest Labs

Family

flux1.1

Ready to integrate?

Access flux1.1-pro-ultra via our unified API.

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Available at 2 providers

Starting from

$0.060 /image via fal.ai, Replicate

Prices shown are in USD

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Providers & Pricing (2)

FLUX1.1 [pro] Ultra is available from 2 providers, with per-image pricing starting at $0.06 through fal.ai.

fal.ai

fal/flux1.1-pro-ultra

Provider Model ID: fal-ai/flux-pro/v1.1-ultra

$0.060 /image

View pricing details

Replicate

replicate/flux1.1-pro-ultra

Provider Model ID: black-forest-labs/flux-1.1-pro-ultra

$0.060 /image

View pricing details

flux-pro-1.1-ultra API OpenAI-compatible

Integrate Black Forest Labs' premium FLUX1.1 [pro] Ultra model via Lumenfall’s OpenAI-compatible API to generate high-fidelity, professional-grade images from text prompts.

Base URL

https://api.lumenfall.ai/openai/v1

Model

flux1.1-pro-ultra

Code Examples

Text to Image

/v1/images/generations

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-ultra",

    "prompt": "",

    "size": "1024x1024"

}'

# Response:

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

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-ultra',

  prompt: '',

  size: '1024x1024'

});

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

console.log(response.data[0].url);

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-ultra",

    prompt="",

    size="1024x1024"

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

print(response.data[0].url)

Parameter Reference

Required Supported Not available

Core Parameters

Parameter	Type	Description	Modes
`prompt`	string	Required. Text prompt for image generation	T2I

Size & Layout

Parameter	Type	Description	Modes
`size`	string	Image dimensions as WxH pixels (e.g. "1024x1024") or aspect ratio (e.g. "16:9") WxH determines both shape and scale (aspect_ratio and resolution are ignored when size is provided). W:H format is equivalent to aspect_ratio.	T2I
`aspect_ratio`	string	Aspect ratio of the output image (e.g. "16:9", "1:1") Controls shape independently of scale. Use with resolution to control both. If size is also provided, size takes precedence. Any ratio is accepted and mapped to the nearest supported value.	T2I
`resolution`	string	Output resolution tier (e.g. "1K", "4K") Controls scale independently of shape. Higher tiers produce larger images and cost more. If size is also provided, size takes precedence for scale. Any tier is accepted and mapped to the nearest supported value.	T2I

size

Exact pixel dimensions

"1920x1080"

aspect_ratio

Shape only, default scale

"16:9"

resolution

Scale tier, preserves shape

"1K"

Priority when combined

size › aspect_ratio + resolution › aspect_ratio › resolution

size is most specific and always wins. aspect_ratio and resolution control shape and scale independently.

How matching works

Shape matching – we pick the closest supported ratio. Ask for 7:1 on a model with 4:1 and 8:1, you get 8:1.

Scale matching – providers use different tier formats: K tiers (0.5K 1K 2K 4K) or megapixel tiers (0.25 1). If the exact tier isn't available, you get the nearest one.

Dimension clamping – if a model has pixel limits, we clamp dimensions to fit and keep the aspect ratio intact.

Output & Format

Parameter	Type	Description	Modes
`response_format`	string	How to return the image `url` `b64_json` Default: `"url"`	T2I
`output_format`	string	Output image format `png` `jpeg` `gif` `webp` `avif` Gateway converts to requested format if provider doesn't support it natively.	T2I
`output_compression`	integer	Compression level for lossy formats (JPEG, WebP, AVIF)	T2I
`n`	integer	Number of images to generate Default: `1` Gateway generates multiple images in parallel even if provider only supports 1.	T2I

Parameter Normalization

How we handle parameters across different providers

Not every provider speaks the same language. When you send a parameter, we handle it in one of four ways depending on what the model supports:

Behavior	What happens	Example
`passthrough`	Sent as-is to the provider	style, quality
`renamed`	Same value, mapped to the field name the provider expects	prompt
`converted`	Transformed to the provider's native format	size
`emulated`	Works even if the provider has no concept of it	n, response_format

Parameters we don't recognize pass straight through to the upstream API, so provider-specific options still work.

Full API Reference Authentication, endpoints, and more

Gallery

View all 3 images

FLUX1.1 [pro] Ultra FAQ

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

FLUX1.1 [pro] Ultra starts at $0.06 per image through Lumenfall. Pricing varies by provider. Lumenfall does not add any markup to provider pricing.

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

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

Which providers offer FLUX1.1 [pro] Ultra?

FLUX1.1 [pro] Ultra 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] Ultra?

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

Overview

FLUX1.1 [pro] Ultra is a high-resolution text-to-image model developed by Black Forest Labs. As an enhanced evolution of the standard FLUX1.1 [pro] architecture, it is specifically engineered to produce premium, photography-grade outputs at significantly higher pixel counts. The model is distinctive for its ability to maintain compositional coherence and fine-textured detail while operating at extreme resolutions.

Strengths

Ultra-High Resolution Output: Unlike base models that often degrade or repeat patterns at high resolutions, this version is optimized for large-scale generations up to 4 megapixels while maintaining structural integrity.
Photorealistic Texture Rendering: The model excels at reproducing complex surface details, such as skin pores, fabric weaves, and atmospheric effects, making it suitable for professional-grade photography emulation.
Improved Prompt Adherence: It demonstrates high fidelity to complex, multi-part instructions, accurately placing objects and satisfying specific lighting or stylistic requirements defined in the prompt.
Speed Efficiency: Despite the increase in output resolution and quality, the model maintains the competitive inference speeds introduced with the FLUX1.1 architecture, offering a faster workflow than many comparable high-resolution diffusion models.

Limitations

Cost Per Generation: With a starting price of roughly $0.06 per image, it is significantly more expensive than “dev” or “schnell” variants, making it less ideal for rapid prototyping or high-volume testing.
Hardware and Latency: Generating images at ultra-high resolutions requires substantial VRAM and compute time; even with optimizations, the time-to-first-pixel is longer than the standard FLUX1.1 [pro] version.
Over-Refinement: In certain artistic contexts, the model’s bias toward “premium” and sharp textures may result in an overly polished look that requires specific prompting to achieve a more muted or “lo-fi” aesthetic.

Technical Background

FLUX1.1 [pro] Ultra is built upon the Flow-based transformer architecture characteristic of the Black Forest Labs lineup. It utilizes a rectified flow scaling approach, which streamlines the sampling process to achieve high-quality results in fewer steps than traditional latent diffusion models. The “Ultra” designation refers to specific fine-tuning and scaling adjustments designed to handle expanded canvas sizes without the tiling artifacts common in earlier diffusion generations.

Best For

This model is best suited for professional workflows where final-asset quality is paramount, such as digital advertising, high-fidelity concept art, and print-ready media. It shines in scenarios requiring hyper-realistic human portraits or intricate architectural visualizations.

FLUX1.1 [pro] Ultra is available through Lumenfall’s unified API and playground, allowing developers to integrate ultra-high resolution image generation into their applications with a single standardized interface.

Try FLUX1.1 [pro] Ultra in Playground

Generate images with custom prompts — no API key needed.

Open Playground