ComfyUI Boolean Expressions

A collection of logic and comparison nodes for ComfyUI.
This package adds building blocks for boolean logic, arithmetic comparisons, and string comparisons, making it easier to design conditional workflows directly in ComfyUI.

✨ Features

• Boolean logic (And, Or, Not, etc.)
• Arithmetic comparisons (<, >, =, …)
• String comparisons (contains, starts with, ends with, …)
• Conditional Branch (if–then–else logic flow)
• Organized under Boolean Expressions category
• Works with booleans, numbers, and strings

Use these nodes to:

• Switch between inputs based on conditions.
• Build parameterized prompts.
• Compare numbers or strings dynamically.
• Create reusable logical subgraphs.

📦 Installation

With ComfyUI Manager

1. Open ComfyUI Manager in your ComfyUI installation.
2. Search for ComfyUI-BooleanExpression.
3. Click Install.

Manual install

Clone this repository into your custom_nodes folder:

cd ComfyUI/custom_nodes
git clone https://github.com/marco-zanella/ComfyUI-BooleanExpression.git

Restart ComfyUI, and the nodes will appear under the Boolean Expressions category.

📸 Examples

Conditional Latent Image

This workflow demonstrates how a boolean toggle can control whether generation begins from an empty latent image or from a selected input image converted into latent space. Two Conditional Branch nodes manage the logic: the first selects which latent image to use, while the second determines the correct denoise factor, applying a user-defined value when starting from an existing image and defaulting to 1.0 when starting from an empty latent.

Download this workflow

Conditional Format Prompt

This workflow demonstrates how to automatically select prompts optimized for square, portrait, or landscape images based on the configured width and height. Arithmetic comparison nodes (Equal to and Less than) determine the image’s aspect ratio, and two Conditional Branch nodes then return the appropriate prompt.

Download this workflow

🔧 Detailed Node List

Boolean Logic

• False
• True
• Not
• And
• Or
• Xor
• Nand
• Nor
• Binary Expression
• Conditional Branch (if–then–else)

Arithmetic Comparison

• Less than
• Less than or equal to
• Equal to
• Not equal to
• Greater than or equal to
• Greater than
• Binary Comparison

String Comparison

• Comes before (alphabetical less than)
• Comes before or equal to
• Equal to
• Not equal to
• Comes after or equal to
• Comes after
• Contains
• Does not contain
• Starts with
• Does not start with
• Ends with
• Does not end with
• String Comparison