Ready to use inside ComfyUI without depending on the UVR desktop application
Supports auto, cuda, directml, and cpu execution providers
Splits input audio into instrumental_audio and vocals_audio
Automatically resamples audio to 44.1 kHz for inference and restores the original sample rate on output
Handles mono input by duplicating it to stereo before separation

Node

Node name: UVR MDX Inst HQ5 Separator
Category: audio/uvr

Inputs

audio: ComfyUI AUDIO
device: auto / cuda / directml / cpu
segment_seconds: chunk size for long audio, default 15
margin_seconds: overlap between chunks, default 1
denoise: enables the common UVR denoise inference trick
compensation: output gain compensation, default 1.01
batch_index: which item to read from a batched AUDIO input

Outputs

instrumental_audio
vocals_audio
info

Requirements

ComfyUI usually already provides torch. This node additionally needs:

numpy
One ONNX Runtime package:
- onnxruntime for CPU
- onnxruntime-gpu for NVIDIA CUDA
- onnxruntime-directml for DirectML on Windows

Installation

Copy or clone this repository into your ComfyUI/custom_nodes/ folder.
Make sure the model file exists at models/UVR-MDX-NET-Inst_HQ_5.onnx.
Install dependencies in the same Python environment used by ComfyUI:

pip install -r requirements.txt

If you want GPU acceleration, replace the default ONNX Runtime package with the variant that matches your system.

Repository Layout

comfyui_uvr_mdx/
|- __init__.py
|- nodes.py
|- README.md
|- README.zh-CN.md
|- requirements.txt
|- LICENSE
`- models/
   `- UVR-MDX-NET-Inst_HQ_5.onnx

Model Attribution

This node uses the bundled UVR-MDX-NET-Inst_HQ_5.onnx model from the Ultimate Vocal Remover (UVR) distribution.

Sources:

Official website: ultimatevocalremover.com
Official repository: Anjok07/ultimatevocalremovergui

According to the UVR repository, the models provided in the package were trained by the UVR core developers unless otherwise noted, and third-party developers using UVR models should provide credit to UVR and its developers.

MDX-Net architecture credits listed by UVR:

Kuielab
Woosung Choi

Please verify upstream model redistribution terms before republishing bundled weights.

Notes

The node loads the model from its local models/ directory and does not rely on absolute paths.
The bundled model file is large enough that you may prefer GitHub Releases or another distribution method in the future, but it is still below GitHub's 100 MB file limit.
The LICENSE file applies to the source code in this repository unless otherwise noted.
Before redistributing the bundled model, verify the upstream model's license and redistribution terms.

Troubleshooting

Bundled model not found: place UVR-MDX-NET-Inst_HQ_5.onnx inside models/
This node requires onnxruntime: install a compatible ONNX Runtime package in the ComfyUI Python environment
Provider errors on cuda or directml: switch device to auto or install the correct runtime package for your hardware

License

MIT for the repository source code. See LICENSE.