ComfyUI-Checkpoint-Iterator

ComfyUI Checkpoint Iterator

A custom node for ComfyUI that allows you to easily iterate through all of your downloaded checkpoints sequentially or dynamically. This is extremely useful for testing prompts or settings against a large batch of different models without manually changing the checkpoint loader node each time.

Installation

1. Navigate to your ComfyUI custom_nodes directory.

   cd ComfyUI/custom_nodes
   

2. Clone this repository (or copy the folder into the custom_nodes directory).

   git clone https://github.com/Ni-zav/ComfyUI-Checkpoint-Iterator.git
   

3. Restart ComfyUI.

Usage

1. In the ComfyUI canvas, right-click and go to Add Node -> loaders -> Checkpoint Loader Iterator.
2. Connect MODEL, CLIP, and VAE outputs into your normal pipeline (KSampler, encoders, etc.).
3. (Optional) Connect CKPT_NAME to your filename prefix so each saved image includes the model name.
4. Queue multiple prompts from the main queue controls.

Iteration behavior

This node has no index input now. It advances automatically on each execution.

• 1st execution -> checkpoint 0
• 2nd execution -> checkpoint 1
• ...
• wraps with modulo when it reaches the end

Memory behavior

Before loading the next checkpoint, the node unloads previous models and clears cache to reduce VRAM carry-over between checkpoints.

Important note about "batch"

KSampler latent/image batch size is not the same as queue iteration count. To iterate checkpoints, queue multiple executions (prompt queue), not just a larger sampler batch size.

How it works

For each image generated in the batch queue, the Primitive node will increment the batch index by 1. The custom node calculates index % total_checkpoints to select the corresponding checkpoint from your models folder and loads it.

Outputs

• MODEL, CLIP, VAE: The standard outputs required for ComfyUI workflows.
• CKPT_NAME: (String) The exact filename of the checkpoint currently loaded. You can route this string into a custom "Save Image" node to automatically include the model name in your generated image filenames for easy comparison.

License

MIT License