Image Comparer Plus

Image Comparer Plus takes two images and gives you a way to look at them side by side, right inside the graph - no tabbing between two Preview Image nodes, no squinting at thumbnails trying to spot the difference. Feed it a before and an after, and it also quietly saves both to your ComfyUI output directory while it's at it.

Why you'd reach for it

The classic use case is any A/B comparison: base render versus upscaled, before versus after inpainting, one seed against another, one sampler against a different one. You could eyeball two separate Preview Image nodes stacked in the graph, but a dedicated comparer built for exactly this - usually a slider or side-by-side view - makes the difference actually visible instead of something you have to hunt for. It's the same job rgthree-comfy's own Image Comparer does in that pack; if you're already used to reaching for that one, this is SKBundle's version of the same idea.

How it works

Two required inputs, image_a and image_b. Beyond that, per the node's own description, it saves both images to your output directory when it runs - worth knowing before you queue a big batch of comparisons, since that means disk writes happen automatically, not just a visual comparison, even if you never added a separate Save Image node for either image.

Inputs and outputs

image_a and image_b are the two images you're comparing - that's the entire input surface. There are no outputs. This is a genuine dead end in your graph by design: it's marked as an output/terminal node, so it's meant to sit at the tail of a branch, not feed anything downstream. If you're chaining a comparison mid-pipeline expecting to pass something onward from here, that's not how this node works - put it at the end.

Installing it

Part of ComfyUI SKBundle, u/skbphy's personal node collection - built with Cursor AI's help by someone who's said openly they're not a professional programmer, with rgthree and mxToolkit named as the influence behind the whole pack. Through ComfyUI Manager, search ComfyUI SKBundle. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/SKBv0/ComfyUI_SKBundle.git
pip install -r requirements.txt

Restart ComfyUI afterward. No models to fetch - it's an image-viewing utility.

Common issues

The one thing that catches people off guard is the lack of outputs - if you go looking for a socket to keep the comparison flowing into the rest of your graph, there isn't one; this node is meant to be a leaf, not a pass-through, so plan your branch layout with that in mind. The other thing worth knowing: since it saves both images to disk automatically, running it repeatedly while iterating on a workflow will quietly accumulate output files even for comparisons you were only doing to check something mid-session - keep an eye on your output directory if you're comparing a lot.