🔧 Simple Math Boolean

This is the least glamorous node in the whole pack and that's exactly why it's useful. Simple Math Boolean is a single toggle that outputs true or false. That's the entire node. You flip it, and whatever downstream logic reads that boolean branches accordingly.

If you've never needed one, you will the moment you start wiring conditional behavior into a workflow.

What it does

One input, one output. The input value is a BOOLEAN (defaults to false), and the output is that same BOOLEAN. You set it in the node's widget and it emits the constant.

Why does a constant deserve its own node? Because in a graph, a value has to come from somewhere to travel down a wire. When another node expects a boolean input - an "enable this branch?" toggle, a switch that picks between two paths, a gate on an optional step - Simple Math Boolean is the clean, labeled source for that true/false. Instead of burying the flag inside some other node's settings, you get one obvious switch on the canvas that says exactly what it controls.

Where it fits

It shines in workflows built for reuse. Say you've got a template that can optionally run an upscale pass, or optionally apply a LoRA, or optionally do a face fix. You wire a Simple Math Boolean to the enable input of each optional stage. Now toggling the whole feature is one visible click, not a dig through node internals. Combine it with the other logic nodes in this pack - Simple Comparison spits out a boolean, Simple Math Condition consumes conditions - and you can build genuinely conditional graphs.

It's the same role a boolean primitive plays in any programming language: a named on/off you can point multiple things at.

Installing it

Simple Math Boolean is part of ComfyUI Essentials by cubiq - Matteo Spinelli, the developer behind the widely-used ComfyUI_IPAdapter_plus, so the pack comes from a trusted source:

• ComfyUI Manager: search "ComfyUI Essentials" → Install → restart.
• Manual: cd ComfyUI/custom_nodes && git clone https://github.com/cubiq/ComfyUI_essentials, install requirements.txt, restart.

The pack's nodes carry a 🔧 wrench in the title and a + in the class name (SimpleMathBoolean+).

Worth knowing

ComfyUI's conditional/switching support has always been a bit ad hoc - there's no single blessed "if" primitive in core - which is why little utility nodes like this exist across several packs. If you're already running pysssss's Custom Scripts or KJNodes, you may have equivalents; there's no harm in that, and no need to install Essentials just for this one node if you've got another boolean source you like.

Gotchas

There's genuinely not much to break here - it's a constant emitter. The only real caveat is pack-level: cubiq set ComfyUI Essentials to maintenance-only in April 2025. The community read is that the nodes still work fine, and something this simple is the last thing that'd break. But if it ever goes red as a "missing node" after a ComfyUI update, that's the pack failing to load - check your startup log for an import error and reinstall through Manager, or roll ComfyUI back to the version that worked. No fixes are coming from upstream, so you're your own maintainer here.