Preset Float [BETA]

Every ComfyUI user has hit the same small tragedy: you're dragging a denoise slider, it goes a hair past 1.0, and suddenly your clean render is static noise because you fed an out-of-range value to a model that assumed you'd stay in bounds. PresetFloatNode (display Preset Float [BETA]) exists so that doesn't happen. It's a float slider with preset ranges and step sizes baked in, and it clamps and rounds your value to fit whichever preset you picked. It's part of DemonAlone-JS_Addon-ComfyUI and, per the pack's own credits, is based on the Power Primitive node from rgthree-comfy - the quality-of-life pack that popularized "one node, one typed value, fanned out everywhere."

How it works

The honest mechanism is a bit clever and a bit of a compromise. ComfyUI reads a node's input definitions once at startup, so the node can't rebuild its widget ranges live when you change the dropdown. Instead the slider stays wide - 0 to 1000 - and the validation happens in execute(): it clamps your value to the selected preset's min/max, then snaps it onto the preset's step grid and rounds off floating-point dust. So the widget feels like a universal slider, and the output is guaranteed sane.

The presets, straight from the source:

• Denoise (0.0 – 1.0, step 0.01) - default 0.5
• CFG Scale (1.0 – 30.0, step 0.5) - default 8.0
• FPS (1 – 120, step 1) - default 24.0
• Strength (0.0 – 2.0, step 0.05) - default 1.0

That's the whole point: Denoise is the only preset where the slider can't exceed 1.0, because the node enforces it server-side no matter what you type in.

The inputs and output

Two inputs: preset (the dropdown) and value (the slider, wide range). One FLOAT output with the clamped, stepped result. Wire it wherever a float needs a source - the classic move from the primitive playbook is converting the widget on a KSampler to an input and feeding this one node to it, so one slider drives denoise across five samplers at once. Same idea as a PrimitiveFloat, just with the guard rails attached.

Installing it

cd ComfyUI/custom_nodes
git clone https://github.com/DemonAlone/DemonAlone-JS_Addon-ComfyUI

Or search "DemonAlone-JS_Addon-ComfyUI" in ComfyUI Manager. Restart, and it's under CustomNodes/Presets. No models, no extra dependencies.

Where people get burned

First, the honesty note: the widget doesn't re-range when you switch presets - you might type 50 into the box while CFG Scale is selected and only see it clamped to 30 when the graph runs. That's by design (startup-defined widgets) but it can look like a bug. The clamping is real; it just happens at execution, not while you type.

Second, if you already run rgthree and its Power Primitives, this is a redundancy you can probably skip - rgthree's version is more general. Where PresetFloat earns its place is precisely as the specialized drop-in: a denoise slider that physically cannot leave 0–1, which is a nicer failure mode than a corrupt render when you over-drag. It won't change your results by magic - the same values pass through - but it removes a whole class of "why is this garbage" mistakes from the equation.