---
title: "Ultimate SD Upscale — ComfyUI Node Inputs, Wiring & Troubleshooting"
description: "Complete reference for Ultimate SD Upscale (ssitu/ComfyUI_UltimateSDUpscale) in ComfyUI: input pins (image, model, positive, negative, vae, upscale_by, tile_width, tile_height, seam_fix_mode), output pins (IMAGE), and Windows setup."
canonical: https://comfy.ink/nodes/ultimate-sd-upscale
updated: 2026-10-17
---

# Ultimate SD Upscale

Splits large images into overlapping tiles, runs low-denoise KSampler detail passes on each tile, and blends seams for 4K–8K output. Package: ssitu/ComfyUI_UltimateSDUpscale.

## Facts (2026-10-17)

- **Node / Pack:** Ultimate SD Upscale
- **Category:** custom-pack
- **Inputs:** image, model, positive, negative, vae, upscale_by, tile_width, tile_height, seam_fix_mode
- **Outputs:** IMAGE
- **Source Pack:** ssitu/ComfyUI_UltimateSDUpscale

## What Ultimate SD Upscale does in a ComfyUI graph

Splits large images into overlapping tiles, runs low-denoise KSampler detail passes on each tile, and blends seams for 4K–8K output.

On the canvas, this node accepts `image, model, positive, negative, vae, upscale_by, tile_width, tile_height, seam_fix_mode` and emits `IMAGE`. Every pin is color-coded by data type so you cannot accidentally wire a pixel `IMAGE` tensor into a `LATENT` pin without an intermediate encode step.

## Installation and missing-node recovery on Windows

Ultimate SD Upscale is provided by `ssitu/ComfyUI_UltimateSDUpscale`. Open [ComfyUI-Manager](https://comfy.ink/nodes/comfyui-manager), click **Install Custom Nodes** (or **Install Missing Custom Nodes** if you loaded a workflow with red boxes), and restart the server.

Download the full Windows desktop or portable package at [/download](https://comfy.ink/download) to get started with a clean Python 3.12 environment.

## FAQ

### How do I fix "Ultimate SD Upscale" showing up as a red box in ComfyUI?

Open [ComfyUI-Manager](https://comfy.ink/nodes/comfyui-manager), click **Install Missing Custom Nodes**, install `ssitu/ComfyUI_UltimateSDUpscale`, and restart ComfyUI.

### What are the main inputs and outputs of Ultimate SD Upscale?

Inputs: image, model, positive, negative, vae, upscale_by, tile_width, tile_height, seam_fix_mode. Outputs: IMAGE.

## Related

- [ComfyUI Nodes Reference](https://comfy.ink/nodes)
- [ComfyUI-Manager](https://comfy.ink/nodes/comfyui-manager)
- [How to Fix Red Missing Nodes in ComfyUI Workflows](https://comfy.ink/howto/fix-missing-custom-nodes-red-boxes)
- [ComfyUI Studio Workspace](https://comfy.ink/studio)
- [KSampler & KSampler (Advanced)](https://comfy.ink/nodes/ksampler)

## Download

Free desktop app: [Download Comfy](https://comfy.ink/download)

Markdown mirror: https://comfy.ink/nodes/ultimate-sd-upscale.md