FLUX.1 [dev] Ultra-Fast
FLUX 1.1 Pro is Black Forest Labs' latest AI image generation model, delivering six times faster generation speeds and superior image quality with enhanced prompt accuracy.
Black Forest Labs 
WaveSpeed Fast FLUX image generation with LoRA support
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.
What FLUX.1 [dev] Ultra-Fast supports
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.
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.
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Get Started FreeCommon 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.
Parameters & options
Optional reference image for image-to-image generation.
The 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.
The size of the generated image in pixels (width×height).
The number of denoising steps. More steps generally produce higher quality but take longer.
Controls how closely the generation follows the prompt. Higher values produce results closer to the prompt but may reduce diversity.
Controls the extent to transform the reference image. Only applies when an image is provided. 1.0 means full transformation.
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