DD XNOR Gate

XNOR is the gate that asks whether your two conditions agree. Both true, or both false - either way, output true. One true and one false - output false. It's the exact inverse of XOR, and honestly it's the kind of gate you'll use twice a year. But when "these two things are in the same state" is the question, nothing else states it as cleanly.

Two boolean inputs, expression1 and expression2 (both default to true), one boolean output. The logic: true if expression1 == expression2, false otherwise.

When you'd actually use it

The word for XNOR is "consistency." Two toggles that should match - "source is portrait" and "output should be portrait" - you want the branch to fire when they're the same, and XNOR says exactly that. Or a sanity check: "the mode selector and the model selected are compatible." When both agree, proceed; when they disagree, take the alternate path.

It's also the gate you reach for when you'd otherwise chain XOR through a Not gate. One node instead of two is a small thing, but in a graph that's already crowded, it's the difference between reading "XNOR: both agree" and reverse-engineering two nodes to figure out the same fact.

The honest take

Between you and me, NAND, NOR, and XNOR are the completeness nodes of this pack. AND, OR, and NOT carry the real workload in workflows; the inverted and equality gates exist so that when you need them, they're one node instead of a small construction project. XNOR is that: a construction project compressed. Don't feel like you must use it - but know it's there the day your conditions need to agree.

Defaults, for the record: both inputs default to true, so a fresh XNOR gate outputs true (both-true counts as agreement). That's the correct gate behavior, but if you connect one condition and leave the other unwired, the unwired side silently counts as true and your output may not move the way you expect.

Installing

The usual DD-LogicNodes path: ComfyUI Manager → search DD-LogicNodes → Install → restart, or git clone https://github.com/dumbdemon/DD_LogicNodes into ComfyUI/custom_nodes. No dependencies, no models. Needs a current-enough ComfyUI build for the newer extension API the pack is written against - if the node isn't in the menu, update ComfyUI first.