How to Use Stable Diffusion WebUI Checkpoints in ComfyUI

When working with Stable Diffusion, two of the most commonly used interfaces are Stable Diffusion WebUI (AUTOMATIC1111) and ComfyUI. If you’ve already downloaded multiple checkpoints (model weights) in WebUI, you might wonder: Can these models be used directly in ComfyUI? The answer is yes! This article will provide a detailed guide on how to properly load and use WebUI checkpoints in ComfyUI, along with some important considerations and optimization tips.

What Are Checkpoints (Model Weights)?

In the Stable Diffusion ecosystem, checkpoints (model weights files) are the core of AI image generation. They are typically stored in .ckpt or .safetensors formats and contain all the weight data required to generate images. Different checkpoints serve different purposes, such as:

  • Base models (e.g., SD1.5, SDXL)
  • Stylized models (e.g., anime, oil painting, cyberpunk style)
  • Specialized models (e.g., photorealistic portraits, specific artistic styles)

If you’ve already downloaded multiple checkpoints in Stable Diffusion WebUI (AUTOMATIC1111) and want to use them in ComfyUI, follow these steps.

How to Use WebUI Checkpoints in ComfyUI

Step 1: Locate Your Checkpoint Files

If you have installed models in WebUI (AUTOMATIC1111), they are usually stored in the following directory:

stable-diffusion-webui/models/Stable-diffusion/

The .ckpt or .safetensors files found in this folder are the ones you need to copy to ComfyUI.

Step 2: Copy Checkpoints to ComfyUI

After locating the model files, copy them to ComfyUI’s checkpoint folder at the following path:

ComfyUI/models/checkpoints/

Example:

  • Suppose you have a model file called AnythingV5.safetensors in the WebUI directory. You need to copy it to ComfyUI’s checkpoints/ folder.

Step 3: Load the Checkpoint in ComfyUI

  1. Open ComfyUI
    Start ComfyUI and access the main interface.
  2. Add a Checkpoint Loader Node
    In ComfyUI’s node editor workspace, add a Checkpoint Loader node (right-click and search for Checkpoint Loader).
  3. Select Your Checkpoint Model
    In the Checkpoint Loader node’s dropdown menu, you should see all the checkpoint files stored in the models/checkpoints/ directory. Select the model you want to use.
  4. Connect to VAE and CLIP
    • Connect the Checkpoint Loader output to VAE Decoder (if you need to load a VAE manually).
    • Connect it to CLIP Text Encoder to ensure text prompts are processed correctly.
  5. Done! You’ve now successfully loaded a WebUI checkpoint into ComfyUI—start generating images!

Common Issues & Important Notes

Although WebUI checkpoints can be used directly in ComfyUI, there are a few key considerations:

1. Ensure Correct VAE Files

  • Some checkpoints require a VAE (Variational Autoencoder) to improve image quality.
  • WebUI VAEs are typically stored in stable-diffusion-webui/models/VAE/. Copy the .vae.pt file to ComfyUI/models/vae/ and use the VAE Loader node in ComfyUI to load it.

2. LoRA & Embeddings Compatibility

  • WebUI supports LoRA (Low-Rank Adaptation models) and Textual Inversion Embeddings. ComfyUI can also use these, but they must be placed in the correct directories:
    • LoRA files should be stored in ComfyUI/models/lora/
    • Embeddings files should be stored in ComfyUI/models/embeddings/
  • In ComfyUI, you must manually add LoRA Loader or Textual Inversion Loader nodes to load these models.

3. Compatible Stable Diffusion Versions

  • If you’re using SD 1.5 or SDXL, make sure the checkpoint is compatible with ComfyUI.
  • SDXL requires additional SDXL-specific nodes, or ComfyUI may not process the model correctly.

4. ControlNet and Additional Plugin Support

  • WebUI includes features like ControlNet and IP-Adapter, which may require extra plugins in ComfyUI.
  • You can add ControlNet Loader and IP-Adapter Loader nodes in ComfyUI to enable these features.

Conclusion

Stable Diffusion WebUI’s checkpoints (.ckpt or .safetensors) can be directly used in ComfyUI by placing them in the ComfyUI/models/checkpoints/ folder.
Ensure proper loading of VAE, LoRA, and Embeddings if your model requires these files in WebUI.
ComfyUI requires manual workflow setup, unlike WebUI, but it provides more control and flexibility.
SD 1.5 and SDXL may need different configurations—if you used SDXL in WebUI, make sure SDXL-related nodes are installed in ComfyUI.

If you enjoy using ComfyUI and want to leverage the resources you already have in WebUI, try migrating your checkpoints and experience the flexibility of a node-based workflow!