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Glossary · ComfyUI Basics

What Are Custom Nodes in ComfyUI?

By Earngenix Team ·

⚡ Quick Answer

Custom nodes are extra node types added to ComfyUI by third-party developers rather than the core program. They live in the custom_nodes folder and add things the base install doesn't have — new model loaders, upscalers, masking tools, and more.

Almost every advanced ComfyUI workflow relies on at least one custom node, because new models and techniques usually get community support as a custom node pack before (if ever) they're folded into ComfyUI itself.

Where You'll See It

Custom nodes appear in the same right-click Add Node menu as ComfyUI's built-in nodes, usually grouped under the pack's own category. On disk, each installed pack is its own folder inside ComfyUI/custom_nodes/.

Quick Example

ComfyUI-GGUF is a custom node pack that adds GGUF model loader nodes. Without installing it, ComfyUI has no way to load a GGUF-quantized checkpoint — the loader node simply doesn't exist yet on a fresh install.

A single custom node pack often bundles several related node types, not just one — installing "ComfyUI-GGUF" gives you a UNet loader, a CLIP loader, and more at once.

Frequently Asked Questions

When you load a workflow, any node type ComfyUI doesn’t recognize appears on the canvas with a red border and an error badge. That’s your signal to install the missing custom node pack, usually through ComfyUI Manager.

Most popular ones are safe and widely used, but a custom node can run any Python code on your machine. Stick to node packs from recognizable maintainers with an active GitHub repo, and be cautious with obscure, unmaintained ones.

Yes. ComfyUI loads all node definitions once at startup, so a newly installed custom node pack won’t appear in the node menu or resolve red nodes until you restart the ComfyUI server.

See It In Action

Got red nodes in a downloaded workflow?

Our guide covers finding and installing exactly the custom nodes a workflow needs.

Published: 2026-09-17 · Last updated: 2026-09-17

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