Multiply

You've got a number coming out of one node and you need it times something before it goes into the next. That's the whole job of Multiply. Two inputs in, their product out. No options, no UI, no drama.

Where it earns its place is inside workflows that compute their own settings instead of hardcoding them. Maybe you're driving a latent dimension off a base resolution and a scale factor, or scaling a ControlNet strength up and down programmatically, or making a step count some multiple of a counter. Rather than typing the final number into every field by hand, you wire the math into the graph and let it fall out. That's the entire reason a math-node pack exists in the first place: core ComfyUI gives you samplers and loaders, not arithmetic.

Multiply ships in ComfyUI-LogicUtils, a grab-bag of logic and math nodes from aria1th, the handle better known as AngelBottomless, the trainer behind Illustrious XL. That's worth knowing because it sets expectations. This is a researcher's personal toolkit, not a polished product, and the README basically apologizes that there are too many nodes to document. So the nodes are terse and you learn them by wiring, not by reading a manual that doesn't exist.

How it works

Two required inputs, input1 and input2, and one output. All three are typed *, the ComfyUI wildcard, meaning "anything." Feed it two numbers, get their product, done.

The wildcard typing is the one thing to actually understand here. ComfyUI normally stops you from connecting mismatched types, but a * port connects to anything, so nothing warns you if you accidentally wire an image or a string into a math node. It'll either error at runtime or hand you something strange. Convenient and a little dangerous, which is the same trade-off the community keeps arguing about with "anything-goes" style nodes that make workflows hard to debug.

There's nothing else to set. The output is whatever input1 * input2 comes to, passed straight into the next node's input.

Installing it

Two ways, pick one.

• ComfyUI Manager: open Manager, go to Custom Nodes Manager, search "ComfyUI-LogicUtils," hit install, restart.
• Manual: cd ComfyUI/custom_nodes && git clone https://github.com/aria1th/ComfyUI-LogicUtils, then restart ComfyUI.

No models to download and no heavy dependencies. It's pure Python math. The pack does carry an optional auto-installer for its dependencies that's off by default; you'd opt in with the env var COMFYUI_LOGICUTILS_AUTO_INSTALL=1, or hard-disable it with COMFYUI_LOGICUTILS_SKIP_INSTALL=1. For Multiply you'll never touch either.

Where people get tripped up

Two things. First, the wildcard trap above: if the result is nonsense, check you're actually feeding numbers and not, say, a string that got "multiplied" as text. Second, output type. Multiply doesn't force an integer. Two ints give you an int, but bring a float into it and the result is a float, which some downstream fields (step counts, dimensions) will refuse. If a node won't accept the wire, drop a Round in between to snap it back to a clean integer.

And if you loaded someone else's workflow and ComfyUI complained it couldn't find "MultiplyNode," that's just this pack not being installed. Grab it and the node reappears. That missing-node dance is honestly how most people meet LogicUtils nodes in the first place: as a quiet dependency buried inside a shared graph, not as something they went looking for.