False

A node that just outputs false sounds like the most useless thing a pack could ship. It's not. ComfyUI's graph is a web of explicit connections, and sometimes you need a guaranteed false on a wire - a branch you want to pin shut, a condition you want to force off for a test, a default that should never accidentally be truthy. That's what this node is: a constant, and nothing more.

It's from marco-zanella's ComfyUI-BooleanExpression pack, the dependency-free logic collection. The pack ships both True and False as explicit constants because hard-coding a boolean into a node is a surprisingly common thing to need. The "False" node you're looking at is the same story as its twin, just inverted.

How it works

There's nothing to configure - no inputs at all. It has a single output, named false, of type BOOLEAN, and it always, unconditionally emits False. The whole implementation is return (False,). This is genuinely all there is.

So when do you actually use it?

• Pin a branch off for testing. Force a Conditional Branch's condition to false so it reliably takes the if_false path while you iterate on that half of the graph, then swap in the real condition when you're done.
• Provide an explicit default. If a node expects a BOOLEAN and you want the workflow to always take the negative route unless something else overrides it, an explicit False is clearer than an unconnected port.
• Debug boolean chains. When a compound And/Or/Nand expression is misbehaving, temporarily dropping a constant in place of one leg isolates whether the logic or the input is at fault.

Installing it

Same story as every node in this pack: zero dependencies, zero models, pure Python. Install via ComfyUI Manager (search ComfyUI-BooleanExpression) or the manual route:

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

Restart ComfyUI and it's under Boolean Expressions, alongside its True twin.

Gotchas

• Don't reach for it as a "keep this node from running" switch. It emits a boolean; it doesn't bypass or mute anything. If you want to disable a whole branch, mute/bypass the branch in the UI - that's separate from boolean logic.
• It's a value, not a wire label. The output socket is named false, which reads fine in most spots but can confuse a busy graph ("did I wire a constant or an actual result here?"). That's the nature of constants; just know what you're looking at.

Honestly, if you never install this specific node you'll survive - the pack's False and True are conveniences more than necessities. But they're free, they cost you nothing at runtime, and the moment you're knee-deep in a conditional workflow and need a reliable false, you'll be glad they're one right-click away.