Boolean Invert (CRT)

There's not much mystery here, and that's the point. Boolean Invert flips true to false and vice versa. It's the kind of node you don't think about until you don't have it - the moment you need "run this branch when the switch is OFF" instead of "when it's ON," and every existing boolean in your graph is wired the wrong way round.

What it's for

ComfyUI graphs accumulate booleans fast: "enable upscale," "use refiner," "skip if cached." They're almost always phrased as an affirmative toggle, because that's how a checkbox widget reads naturally in the UI. But logic gates and conditional-execution nodes downstream frequently need the opposite condition, and rewiring the source widget itself just breaks it for the branch that wanted the original polarity. Rather than duplicate a widget or maintain two copies of the same toggle, you drop one Boolean Invert between the source and whichever branch wants the inverse, and move on.

It also comes up when you're consuming a boolean from somewhere you don't control - another node's output, an Any Trigger-style presence check, a saved workflow value - and the polarity just happens to be backwards for what you need.

The inputs and outputs that matter

One input, required:

• input_boolean - BOOLEAN, defaults to true.

One output:

• output_boolean - BOOLEAN, the inverse of the input.

That's the entire node. No hidden modes, no string parsing, no edge cases to worry about - feed it true, get false, and back again.

Installing it

Boolean Invert lives in the CRT/Logic category of the CRT-Nodes pack, alongside Any Trigger and Strength to Steps. It's part of PGCRT's (CRYPT_EXE's) larger CRT-Nodes suite - you get the whole pack, not just this node.

ComfyUI Manager - search CRT-Nodes, install, restart.

Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/PGCRT/CRT-Nodes.git
pip install -r requirements.txt

Restart ComfyUI. Nothing extra to download - this node has zero external dependencies beyond the pack loading at all.

Common issues

There genuinely isn't much that goes wrong with a node this simple. The only real failure mode worth naming:

• The node is missing from the picker after install. Since Boolean Invert has no optional imports of its own, that means something else in CRT-Nodes failed to import at startup - the pack is written to keep loading and only drop the specific nodes whose dependencies are missing, so a partial install elsewhere in the pack won't take this one down with it under normal circumstances. Check the ComfyUI console log at startup for a traceback; it'll name the node that actually failed.
• Confusing it with a full boolean-logic suite. If you need AND/OR/XOR across multiple booleans, this pack has other utility nodes for that (Boolean Transform, and CRT's broader Utils/Logic & Values category) - Boolean Invert only ever does one thing, and that's by design.