ComfyUI pi-Flow Nodes for Fast Few-Step Sampling

ComfyUI-piFlow provides a collection of custom nodes for ComfyUI that implement the pi-Flow few-step sampling workflow. All images in the above example were generated using pi-Flow with only 4 sampling steps.

pi-Flow is a novel method for flow-based few-step generation. It achieves both high quality and diversity in generated images with as few as 4 sampling steps. Notably, pi-Flow’s results generally align with the base model’s outputs and exhibit significantly higher diversity than those from DMD models (e.g., Qwen-Image Lightning), as shown below.

In addition, when using some photorealistic style LoRAs, pi-Flow produces better texture details than DMD models, as shown below (zoom in for best view).

Workflows

This repo provides image generation workflows based on Qwen-Image, FLUX.1 dev, and FLUX.2 dev.

pi-Qwen-Image

Currently supports the Qwen-Image text-to-image base model (and possibly some of its customized versions).

Please download the image below and drag it into ComfyUI to load the pi-Qwen-Image workflow.

Model links

Base model

• Download qwen_image_fp8_e4m3fn.safetensors and save it to
  models/diffusion_models/qwen_image_fp8_e4m3fn.safetensors

  Alternative scaled FP8 version: qwen_image_fp8_e4m3fn_scaled.safetensors

pi-Flow adapter

• Download gmqwen_k8_piid_4step/diffusion_pytorch_model.safetensors and save it to
  models/loras/gmqwen_k8_piid_4step.safetensors

Text encoder

• Download qwen_2.5_vl_7b_fp8_scaled.safetensors and save it to
  models/text_encoders/qwen_2.5_vl_7b_fp8_scaled.safetensors

VAE

• Download qwen_image_vae.safetensors and save it to
  models/vae/qwen_image_vae.safetensors

Sampler steps

The 4-step adapter works well for any number of sampling steps greater than or equal to 4.

pi-Flux

Currently supports the FLUX.1 dev text-to-image base model (and possibly some of its customized versions).

Please download the image below and drag it into ComfyUI to load the pi-Flux workflow.

Model links

Base model

• Download flux1-dev.safetensors and save it to
  models/diffusion_models/flux1-dev.safetensors

  Alternative scaled FP8 version: flux_dev_fp8_scaled_diffusion_model.safetensors

pi-Flow adapter

• Download gmflux_k8_piid_4step/diffusion_pytorch_model.safetensors and save it to
  models/loras/gmflux_k8_piid_4step.safetensors

• Download gmflux_k8_piid_8step/diffusion_pytorch_model.safetensors and save it to
  models/loras/gmflux_k8_piid_8step.safetensors

Text encoder

• Download clip_l.safetensors and save it to
  models/text_encoders/clip_l.safetensors

• Download t5xxl_fp16.safetensors and save it to
  models/text_encoders/t5xxl_fp16.safetensors

VAE

• Download ae.safetensors and save it to
  models/vae/ae.safetensors

Sampler steps

Use gmflux_k8_piid_4step.safetensors for 4-step sampling and gmflux_k8_piid_8step.safetensors for 8-step sampling. Using other settings may result in amplified or reduced contrast, which could be re-calibrated by adjusting the adapter_strength.

Guidance

The adapters only work with guidance set to 3.5. Do NOT modify this value, otherwise the results will be very noisy.

pi-Flux.2

Supports the FLUX.2 dev base model (and possibly some of its customized versions), which enables both text-to-image generation and multi-image editing tasks.

Please download the image below and drag it into ComfyUI to load the pi-Flux.2 workflow.

Model links

Base model

• Download flux2_dev_fp8mixed.safetensors and save it to
  models/diffusion_models/flux2_dev_fp8mixed.safetensors

pi-Flow adapter

• Download gmflux2_k8_piid_4step/diffusion_pytorch_model.safetensors and save it to
  models/loras/gmflux2_k8_piid_4step.safetensors

Text encoder

• Download mistral_3_small_flux2_fp8.safetensors and save it to
  models/text_encoders/mistral_3_small_flux2_fp8.safetensors

VAE

• Download flux2-vae.safetensors and save it to
  models/vae/flux2-vae.safetensors

Sampler steps

The 4-step adapter works well for any number of sampling steps greater than or equal to 4.

Guidance

The adapter only works with guidance set to 4.0. Do NOT modify this value.

GGUF Support

To load GGUF models, please install the custom nodes in ComfyUI-GGUF first.

Then, replace the Load pi-Flow Model node in the workflows with the Load pi-Flow Model (GGUF) node and select the corresponding GGUF model file.

Training Your Own pi-Flow Models

Please visit the official piFlow repo for more information on training.