ComfyUI Extension: ComfyUI Live Preview

Authored by TechnoWarrior2

Created

Updated

4 stars

Run ComfyUI workflows without the setup

No installs, no CUDA version roulette, no GPU sitting idle on your bill. Bring a workflow and run it in the browser.

Displays a large draggable floating window with live denoising step previews as your image generates, similar to A1111 and Forge.

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Custom Nodes (1)

README

ComfyUI Live Preview

A ComfyUI node that displays a large floating overlay window showing live denoising step previews as your image generates — similar to the live preview in A1111 and Forge.

Features

  • Full-size live preview — watch the image form step by step in a large resizable window instead of the tiny built-in thumbnail
  • Draggable and resizable — drag by the header, resize from the bottom-right corner, position it anywhere on screen
  • Step counter and FPS display — shows current step and preview frames per second in the header
  • Status indicator — green dot while generating, purple when done
  • ⚡ Toggle button — persistent floating button in the bottom-right corner of the ComfyUI page to show/hide the window at any time
  • Zero overhead — hooks into ComfyUI's existing websocket preview stream, no extra processing
<img width="248" height="163" alt="Screenshot 2026-05-29 143825" src="https://github.com/user-attachments/assets/2d617bbe-5308-4fee-8f5d-27a397f4d277" /> <img width="1065" height="681" alt="Screenshot 2026-05-29 144904" src="https://github.com/user-attachments/assets/9188f642-9f30-4424-8c9a-6a1d34c76da4" />

Installation

Option 1 — Clone into custom_nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/TechnoWarrior2/comfyui-live-preview

Option 2 — Manual download:

Download the repo as a ZIP, extract it, and place the folder inside ComfyUI/custom_nodes/.

Then restart ComfyUI.

Usage

Find the node by searching Live Preview (Large) in the node menu under the image category.

The node is a simple pass-through — connect IMAGE in and IMAGE out like any other image node, or leave it floating unconnected anywhere in your workflow. Either way the preview window will activate the moment generation starts.

| Input | Output | |-------|--------| | images (IMAGE) | images (IMAGE) — unchanged pass-through |

The ⚡ button in the bottom-right corner of the ComfyUI page toggles the preview window independently of generation — useful for checking the last generation after it finishes.

Notes

  • The preview window only activates when a Live Preview node is present somewhere in the workflow graph
  • ComfyUI must have previews enabled (--preview-method auto or similar) for frames to broadcast — if you're getting no preview frames, check your launch arguments

Updating

cd ComfyUI/custom_nodes/comfyui-live-preview
git pull

Then restart ComfyUI.

Run ComfyUI workflows without the setup

No installs, no CUDA version roulette, no GPU sitting idle on your bill. Bring a workflow and run it in the browser.

Learn more