First Switch

Nifty First Switch is the fallback chain node: you feed it up to 16 inputs of any type, and it returns the first one that isn't None. That's it. But "first non-None" is one of those tiny ideas that saves you from building the same three-node boolean nest over and over.

Think about what a fallback usually looks like in a manual workflow: "use the image the detector found, or if there isn't one, use the previous frame, or if that's missing too, use this static placeholder." That's a chain of if/else checks. Nifty First Switch collapses it into one node with a values input list - top input wins, and it checks top to bottom.

The lazy bit

The values input auto-grows as you connect more, and it's evaluated lazily: ComfyUI stops running inputs as soon as a non-None is found. If value1 is connected and present, value2 through value16 never execute. That matters when your candidates are expensive - a full sampler run as the "nice" option and a cheap placeholder as the last resort. The nice path runs only when it actually produces something.

Output: output - the first non-None value, or None if everything is empty.

Where it shines

• Optional-input handling. Feed it a detected image (which may be None), then a cached/default image. One node instead of an Is None + Input Switch pair.
• Progressive refinement. Try the high-quality path first, fall back to a faster one.
• Prompt/parameter fallbacks - strings work just as well as images, so a missing loaded setting falls back to a hardcoded default.

The main gotcha is the same one every lazy node has: an input that only exists to have a side effect won't run unless earlier inputs are None. If you need candidates to evaluate regardless, you want an eager variant - Nifty Nodes' logic suite is lazy/eager-paired throughout, and this one is the lazy member of the pair.

Install

ComfyUI Manager → search "Nifty Nodes", or:

cd ComfyUI/custom_nodes
git clone https://github.com/Stibo/comfyui-nifty-nodes

Restart ComfyUI, and keep ComfyUI current - the pack runs on the new v3 API. Small pack, small community so far, but this node is a genuine quality-of-life win for anyone building conditional workflows. It reads like a gimmick and turns out to be the thing you wire into every second workflow.