Copy the comfyui-resolution-selector folder into ComfyUI/custom_nodes/ and restart ComfyUI (refresh the browser too, for the live preview script).

Widgets

Widget	Type	Purpose
megapixels	FLOAT (0.01 steps)	Target size, e.g. `4.15`
aspect_width / aspect_height	INT	Ratio terms, e.g. 16 : 9
multiple	INT	Each edge snaps to a multiple of this
use_image	toggle	Off = input image ignored entirely
use_image_ratio	toggle	Use the input image's ratio instead of the ratio widgets
latent_type	dropdown	SD/SDXL (4ch) or Flux/SD3 (16ch) empty latent

Inputs / Outputs (all optional)

image (in): optional image to resize.
latent: empty latent at the generated resolution.
width / height: generated resolution as INTs.
image (out): input image lanczos-resized to cover the target, then center-cropped to fit exactly. None if no image was provided or use_image is off (don't leave it connected in that case).

Behavior

The chosen width/height minimize combined megapixel + aspect-ratio error on the multiple grid, never below multiple per edge.
The generated resolution is shown live at the bottom of the node as you change values. With use_image_ratio on and an image connected, it shows "resolved at runtime" since image dimensions are only known then.
Latent is size/8 per side; with multiple below 8 the latent rounds down, so keep multiple at 8+ for exact latent match. =======

comfyui-resolution-selector

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