ComfyUI-Downloader

A powerful and user-friendly extension for ComfyUI that adds a built-in model downloader with a sleek modal interface. Download models, LoRAs, VAEs, and other assets directly from URLs without leaving ComfyUI.

Fork Notice

This repository is a fork of:

• https://github.com/romandev-codex/ComfyUI-Downloader

Attribution to the original author is preserved. The project remains under the same MIT License.

Fork Changes (czarecki)

This fork adds reliability and UX improvements for model destination paths and missing-model workflow:

• Fixed Windows path handling for model folder detection in backend logic.
• Improved folder validation to allow model-related targets and block non-model folders.
• Added strict match mode and exact installed-path status to reduce false positives.
• Added "Open Folder" action for model rows and fixed delegated click handling.
• Restored the standard menu/button-group Downloader button near ComfyUI Manager (floating mode was rolled back due to stability/UX issues).
• Updated missing-model status styling and action layout for clearer at-a-glance state.

Features

• 🚀 High-Speed Downloads: Optimized for datacenter connections with parallel downloading (8 connections, 32MB chunks)
• 📦 Queue Management: Download multiple files with automatic queue processing
• 🎯 Smart Integration: Detects missing models from your workflow and suggests downloads
• 🔄 Real-time Progress: Live progress tracking with download speed and ETA
• 🛡️ Security: Built-in path traversal protection and file validation
• 📂 Auto-Organization: Downloads files to the correct ComfyUI folders (checkpoints, loras, VAEs, etc.)
• ⏸️ Download Control: Cancel downloads in progress with queue management
• 🎨 Clean UI: Modal-based interface that integrates seamlessly with ComfyUI

👉 Watch Full Video

Models urls are loaded from workflow or https://github.com/Comfy-Org/ComfyUI-Manager/blob/main/model-list.json

Installation

Method 2: Manual Installation

1. Navigate to your ComfyUI custom nodes directory:

   cd ComfyUI/custom_nodes/

2. Clone the fork (recommended for the latest fixes in this repo):

   git clone https://github.com/czarecki/ComfyUI-Downloader.git

   Or clone the upstream/original project:

   git clone https://github.com/romandev-codex/ComfyUI-Downloader.git

3. Install dependencies:

   cd ComfyUI-Downloader
   pip install -r requirements.txt

4. Restart ComfyUI

Requirements

• Python 3.8+
• ComfyUI
• Dependencies:
  • aiohttp
  • hf_transfer

Usage

Basic Usage

1. Click the "Downloader" button in the ComfyUI interface (next to the settings button)
2. The downloader modal will open
3. Paste a model URL in the URL field
4. Select the destination folder (checkpoints, loras, vae, etc.)
5. Enter a filename (supports subfolders like subfolder/model.safetensors)
6. Click "Download"

Advanced Features

Subfolder Support

You can organize downloads into subfolders:

my-loras/character-lora.safetensors
sdxl/checkpoints/my-model.safetensors

File Override Protection

• If a file already exists, you'll be prompted for confirmation
• Choose to override or cancel the download

Missing Model Detection

• The extension scans your workflow for missing models
• Missing models are highlighted in the UI for quick downloading

Queue Management

• Multiple downloads are queued automatically
• One download processes at a time for optimal performance
• Cancel queued or active downloads anytime

Configuration

The extension uses optimized settings for datacenter connections:

• Chunk Size: 32MB (balanced for 500MB to 30GB+ files)
• Parallel Connections: 8 (optimal for datacenter bandwidth)

These settings are configured in the __init__.py file and can be adjusted if needed.

Supported Folders

The downloader supports all standard ComfyUI model directories:

• checkpoints
• loras
• vae
• upscale_models
• embeddings
• controlnet
• clip_vision
• And more...

Security

ComfyUI-Downloader includes multiple security measures:

• Path traversal attack prevention
• Filename validation (no backslashes, dots, or escape sequences)
• Path resolution verification
• Only downloads to configured ComfyUI model directories

API

The extension provides REST API endpoints for programmatic access:

Start Download

POST /{API_PREFIX}/server_download/start
{
  "url": "https://example.com/model.safetensors",
  "save_path": "checkpoints",
  "filename": "model.safetensors",
  "override": false
}

Cancel Download

POST /{API_PREFIX}/server_download/cancel
{
  "download_id": "checkpoints/model.safetensors"
}

WebSocket Events

• server_download_progress: Real-time progress updates
• server_download_complete: Download completion notification
• server_download_error: Error notifications

Development

Project Structure

ComfyUI-Downloader/
├── __init__.py              # Main extension logic and API endpoints
├── requirements.txt         # Python dependencies
├── web/
│   ├── css/
│   │   └── downloader.css  # UI styling
│   └── js/
│       ├── downloader.js   # Extension initialization
│       └── UI.js           # Modal UI implementation
└── README.md

Building and Testing

1. Make your changes
2. Restart ComfyUI to reload the extension
3. Test in the browser console for any errors

Troubleshooting

Button Doesn't Appear

• Ensure ComfyUI is fully loaded before looking for the button
• Check browser console for JavaScript errors
• Verify the extension is in the custom_nodes directory

Downloads Fail

• Check internet connectivity
• Verify the URL is accessible
• Check browser console and ComfyUI terminal for error messages
• Ensure you have write permissions to the ComfyUI directories

Slow Download Speeds

• The extension is optimized for datacenter connections
• Adjust CHUNK_SIZE and NUM_CONNECTIONS in __init__.py if needed
• Check your network bandwidth and latency

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - see LICENSE file for details

Credits

Created for the ComfyUI community to make model management easier and more efficient.

Support

If you encounter issues or have suggestions:

• Open an issue on GitHub
• Check existing issues for solutions
• Provide error messages and browser console logs when reporting bugs