LoRA Style Adaptation
Accepts external LoRA weights to apply fine-tuned styles or subjects without retraining the base model. Enables consistent character, style, or concept application across generations.
Blackforestlabs
FLUX.1 [dev] Ultra-Fast
This variant is optimized for ultra-fast inference, making it suited for iterative creative workflows, rapid prototyping, and applications where generation latency matters. Its input schema includes dual image URL fields, LoRA configuration, selection parameters, numeric controls, and a seed value, giving developers precise control over output dimensions, style, and reproducibility. It is well-suited for graphic designers, developers building image generation pipelines, and creators who need consistent, customizable visual outputs at scale.
Unknown
10,000 context
N/A output
LoRA Style Adaptation
Source Image Input
Seed Control
Numeric Parameter Control
Long Prompt Support
Ultra-Fast Inference
Model Overview
High-signal model metadata in a structured two-column overview table.
Provider
The entity that provides this model.
Blackforestlabs
Input Context Window
The number of tokens supported by the input context window.
10,000
tokens
Maximum Output Tokens
The number of tokens that can be generated by the model in a single request.
N/A
tokens
Open Source
Whether the model's code is available for public use.
No
Release Date
When the model was first released.
Unknown
Knowledge Cut-off Date
When the model's knowledge was last updated.
Unknown
API Providers
The providers that offer this model. This is not an exhaustive list.
Hugging Face
Modalities
Types of data this model can process.
Image
What is FLUX.1 [dev] Ultra-Fast
A fuller summary of positioning, capabilities, and source-specific details for FLUX.1 [dev] Ultra-Fast.
This variant is optimized for ultra-fast inference, making it suited for iterative creative workflows, rapid prototyping, and applications where generation latency matters. Its input schema includes dual image URL fields, LoRA configuration, selection parameters, numeric controls, and a seed value, giving developers precise control over output dimensions, style, and reproducibility. It is well-suited for graphic designers, developers building image generation pipelines, and creators who need consistent, customizable visual outputs at scale.
Capabilities
What FLUX.1 [dev] Ultra-Fast supports
Source Image Input
Takes one or more image URLs as reference inputs to guide the generation process. Supports two separate image URL fields for flexible image-to-image workflows.
Seed Control
Accepts a seed value to make outputs reproducible across runs with identical settings. Useful for iterating on a composition while keeping the random state fixed.
Numeric Parameter Control
Exposes multiple numeric input fields for controlling generation parameters such as steps, guidance scale, or dimensions. Gives developers fine-grained control over output characteristics.
Long Prompt Support
Supports a context window of up to 10,000 tokens, allowing detailed and descriptive text prompts for complex scene descriptions.
Ultra-Fast Inference
Optimized for reduced generation latency compared to standard FLUX.1 [dev] deployments, making it practical for iterative or real-time creative workflows.
Pricing for FLUX.1 [dev] Ultra-Fast
Primary API pricing shown in the same “quick compare” spirit as the reference page.
Input tokens
N/A
Per million tokens
Output tokens
N/A
Per million tokens
API Access & Providers
Places where this model is available, based on the synced detail-page metadata.
Hugging Face
Configuration & Parameters
The configurable options currently documented for this model.
Image
Image URLOptional reference image for image-to-image generation.
Mask Image
Image URLThe mask image tells the model where to generate new pixels (white) and where to preserve the original image (black). It acts as a stencil for targeted image editing.
Size
SelectThe size of the generated image in pixels (width×height).
Num Inference Steps
NumberThe number of denoising steps. More steps generally produce higher quality but take longer.
Guidance Scale
NumberControls how closely the generation follows the prompt. Higher values produce results closer to the prompt but may reduce diversity.
Strength
NumberControls the extent to transform the reference image. Only applies when an image is provided. 1.0 means full transformation.
Seed
SeedSupported Request Parameters
Parameters currently listed by OpenRouter or the local catalog for this model.
Resources & Documentation
Official model cards, release notes, docs, and other references synced from the source page.
FAQ
Common questions about FLUX.1 [dev] Ultra-Fast
What is the context window for FLUX.1 [dev] Ultra-Fast?
The model supports a context window of 10,000 tokens, which applies to the text prompt input used to guide image generation.
Does this model support LoRA weights?
Yes. The model accepts LoRA weights as a direct input, allowing you to apply custom fine-tuned styles or subjects on top of the base FLUX.1 [dev] model without retraining.
Can I use a reference image as input?
Yes. The model's input schema includes two separate image URL fields, enabling image-to-image workflows where a source image guides the generation output.
Is generation output reproducible?
Yes. The model accepts a seed value as an input. Using the same seed with identical parameters will produce consistent, reproducible outputs.
What is the training data cutoff for this model?
The metadata lists the training date as not applicable (n/a), so a specific training data cutoff date is not available for this model.
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