How to Use ComfyUI: Workflows, Models, and Setup

ComfyUI is a free application that enables you to generate AI images and videos locally on your own machine. It is designed for users who require more control than standard prompt-based tools offer, allowing you to visualise and adjust every stage of the generation process. While this flexibility introduces a learning curve, this guide will assist you in getting started, covering everything from installation to running and customising your first workflow.

What You Need Before Starting

Running ComfyUI requires a computer with sufficient GPU resources to handle the models and workflows you intend to use. More complex models and demanding workflows typically require higher VRAM capacity.

You will also need the specific model files required by your workflow. Depending on the type, these may include checkpoints, diffusion models, VAEs, text encoders, LoRAs, or other components. These files are generally stored within the ComfyUI/models directory.

If your local GPU is not suitable, you can run ComfyUI on a remote GPU-powered desktop. This offloads the generation workload to the remote GPU while allowing you to access the interface from your standard computer.

Install ComfyUI

For Windows and macOS users, ComfyUI recommends using its desktop application for a smoother initial experience. Alternative installation methods, such as manual installation or using the ComfyUI command-line tool, are also available. The best method depends on your specific operating system and setup.

Once ComfyUI is installed, launch the application and open the interface. You will see the workflow canvas along with the tools needed to create and manage your workflows.

Why ComfyUI Workflows Matter

A ComfyUI workflow defines the precise method for generating an image or video. It governs the models, settings, and processing steps used to produce the final output.

This offers significantly more control than a simple prompt box. You can modify the model, add a LoRA, use an input image, tweak generation settings, upscale the result, or integrate additional processing steps.

Workflows are also savable and reusable. Rather than reconstructing the same setup repeatedly, you can save a workflow that yields desirable results and adjust individual settings as needed. You can also download workflows created by the community and adapt them to your specific requirements.

Understand a ComfyUI Workflow

A workflow consists of interconnected nodes. Each node handles a specific part of the generation process, and the connections dictate how data flows between them.

A basic text-to-image workflow typically includes nodes for loading the model, entering the prompt, creating initial image data, generating the image, decoding the result, and saving it.

• Model loader: Loads the model used for generation.
• Text encoder: Converts your prompt into data the model can process.
• Sampler: Executes the generation process using the selected settings.
• VAE: Converts between latent data and the final image.
• Save Image: Writes the generated image to disk.

You do not need to build every workflow from scratch. ComfyUI provides workflow templates, and numerous community workflows are available for direct download and use.

Load an Existing Workflow

Using an existing workflow is often the simplest way to begin. ComfyUI offers example workflows for various models and tasks, and community sites provide many additional options.

Many workflow images contain the workflow data in their metadata. You can drag the image into ComfyUI or use Workflows → Open to load it. The workflow will appear on the canvas with its nodes and settings already configured.

After loading the workflow, verify which models it requires. If files are missing, ComfyUI can identify missing models for supported templates. For other workflows, you may need to locate and install the required models yourself.

Find Models for ComfyUI

Models can be found on repositories such as Hugging Face and Civitai, as well as on the project pages for specific models. The key is finding a model compatible with your chosen workflow.

Do not assume that any model file can be loaded into any workflow. Different model architectures may require specific loaders and supporting files.

Before downloading a model, check the following:

• The model architecture and version
• The required ComfyUI workflow
• The model file format
• The recommended VRAM and hardware
• Any required VAE, text encoder, LoRA, or other supporting files
• The model's license and usage restrictions

ComfyUI supports various types of model files. The destination folder depends on the model type. For instance, checkpoints go in models/checkpoints, LoRAs in models/loras, and VAEs in models/vae. Some newer models use folders such as models/diffusion_models and models/text_encoders.

Install a Model

Once you have downloaded a model, place it in the directory expected by the workflow. You can then select it in the corresponding model loader.

For example, a checkpoint might be stored in:

ComfyUI/models/checkpoints/

A LoRA might instead be stored in:

ComfyUI/models/loras/

If the new model does not appear in the model list, refresh the interface or restart ComfyUI.

Install Custom Nodes

Many advanced ComfyUI workflows rely on custom nodes that are not part of the standard installation. If these dependencies are missing, the workflow may display errors for missing nodes.

ComfyUI provides a Manager for installing custom nodes. Alternatively, nodes can be installed manually by placing their repositories in the custom_nodes directory and installing their required dependencies.

Only install custom nodes from trusted sources. Custom nodes can contain executable code and may have their own dependencies and security considerations.

Run and Modify Your Workflow

Once the required models and custom nodes are installed, review the key settings in the workflow. Start by checking the model, prompt, image dimensions, and sampling settings.

When everything is ready, use the Queue button to execute the workflow. ComfyUI will process each step and produce the output defined by the workflow.

You can then modify individual parts of the workflow without rebuilding it. Add a LoRA, connect an input image, change the sampler, add an upscaler, or adjust other settings to refine the result.

Save Your Workflows

Save workflows that you intend to reuse. A workflow contains the node graph and its settings, but it does not necessarily include the model files themselves. Keep track of which models and custom nodes the workflow requires.

This is especially important when moving a workflow to another computer or cloud desktop. You may need to install the same models and custom nodes before the workflow will run correctly.

Try ComfyUI on DaDesktop

You do not need to purchase a new GPU just to run ComfyUI. If your current computer lacks sufficient GPU resources, you can run ComfyUI on a cloud desktop and access it when needed.

DaDesktop provides cloud desktops with dedicated GPU resources for workloads such as AI image and video generation. You can install ComfyUI, download your desired models, and build your own workflows without adding a dedicated GPU to your local computer.

Learn more about AI image and video generation on DaDesktop. You can also view the available GPUs and choose a configuration based on the models and workflows you want to run.