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# Flux

Flux is a series of text-to-image generation models based on diffusion transformers. To know more about Flux, check out the original [blog post](https://blackforestlabs.ai/announcing-black-forest-labs/) by the creators of Flux, Black Forest Labs. 

Original model checkpoints for Flux can be found [here](https://huggingface.co/black-forest-labs). Original inference code can be found [here](https://github.com/black-forest-labs/flux).

<Tip>

Flux can be quite expensive to run on consumer hardware devices. However, you can perform a suite of optimizations to run it faster and in a more memory-friendly manner. Check out [this section](https://huggingface.co/blog/sd3#memory-optimizations-for-sd3) for more details. Additionally, Flux can benefit from quantization for memory efficiency with a trade-off in inference latency. Refer to [this blog post](https://huggingface.co/blog/quanto-diffusers) to learn more. 

</Tip>

Flux comes in two variants:

* Timestep-distilled (`black-forest-labs/FLUX.1-schnell`)
* Guidance-distilled (`black-forest-labs/FLUX.1-dev`)

Both checkpoints have slightly difference usage which we detail below. 

### Timestep-distilled

* `max_sequence_length` cannot be more than 256. 
* `guidance_scale` needs to be 0.
* As this is a timestep-distilled model, it benefits from fewer sampling steps.

```python
import torch
from diffusers import  FluxPipeline

pipe = FluxPipeline.from_pretrained("black-forest-labs/FLUX.1-schnell", torch_dtype=torch.bfloat16)
pipe.enable_model_cpu_offload()

prompt = "A cat holding a sign that says hello world"
out = pipe(
    prompt=prompt, 
    guidance_scale=0., 
    height=768, 
    width=1360, 
    num_inference_steps=4, 
    max_sequence_length=256,
).images[0]
out.save("image.png")
```

### Guidance-distilled

* The guidance-distilled variant takes about 50 sampling steps for good-quality generation.
* It doesn't have any limitations around the `max_sequence_length`. 

```python
import torch
from diffusers import  FluxPipeline

pipe = FluxPipeline.from_pretrained("black-forest-labs/FLUX.1-dev", torch_dtype=torch.bfloat16)
pipe.enable_model_cpu_offload()

prompt = "a tiny astronaut hatching from an egg on the moon"
out = pipe(
    prompt=prompt, 
    guidance_scale=3.5, 
    height=768, 
    width=1360, 
    num_inference_steps=50,
).images[0]
out.save("image.png")
```

## FluxPipeline

[[autodoc]] FluxPipeline
	- all
	- __call__