easy isNone

easy isNone answers one yes/no question: is this thing empty? Feed it anything - an image, a latent, a string, a model, nothing at all - and it returns a boolean that's true when the input is None and false when it isn't. That's the whole node, and if you're building any kind of conditional graph you'll want it in your pocket.

It's a logic helper from yolain's ComfyUI-Easy-Use pack, part of the "lazy if/else and for loops" toolkit the pack added to make ComfyUI graphs behave a little more like a program with branches. On its own it does nothing visible. Wired into an easy ifElse, it becomes the switch that decides which branch runs.

Why you need it

ComfyUI has optional inputs - sockets a node can run with or without. The problem is knowing, at runtime, whether one got connected. isNone is how you test that. The canonical use: a node has an optional image input, and you want to generate an image when none is provided but use the one that's passed when it is. Route the optional input into isNone, feed the boolean into an ifElse, and you've built exactly that "use it if present, otherwise make one" logic.

More generally it's the guard clause of ComfyUI. Any time your graph should do one thing when a value exists and another when it doesn't, isNone is the primitive that reads the state so a branch node can act on it.

Inputs and outputs

• Input: any - wildcard-typed (*), so it accepts literally anything, including an unconnected optional.
• Output: boolean - true if the input is None/empty, false otherwise.

Wire the boolean into a branch (easy ifElse), a while-loop's condition, or anywhere a BOOLEAN steers behavior.

Installing it

Ships with the pack. ComfyUI Manager → "ComfyUI Easy Use" → install → restart. Or cd ComfyUI/custom_nodes && git clone https://github.com/yolain/ComfyUI-Easy-Use, run install.bat / pip install -r requirements.txt, restart.

Common issues

Worth knowing: easy isNone had a bug that was fixed in v1.3.5. If you're on an older copy of the pack and the node is returning nonsense - false when the input is clearly empty, or vice versa - update the pack before you spend an evening debugging your own graph. It works correctly on current versions.

The other thing is just conceptual: isNone tells you presence, not content. It reports whether a value exists, not whether it's "valid" or non-blank in some richer sense - an empty-string input that's still technically connected is a real value, not None. If you need "is this string empty" rather than "is this socket unconnected," that's a different check. For its actual job - detecting a missing optional so a branch can react - it's exactly the right tool, and it's the piece most conditional EasyUse graphs quietly depend on.