(Deno) Image Compare

You don't always need to export a comparison image. Sometimes you just need to look: is the upscale actually better, did the LoRA change the face, which of these two seeds wins? (Deno) Image Compare is the pack's visual A/B tool for that exact moment - it takes image_a and image_b, shows them side by side (or under a slider, or as a difference view), and deliberately has no output connection, because it's built for inspection, not for the pipeline.

How it works

Four views, one node:

• Slider (default) - the classic before/after wipe. Hover and move the mouse to slide the divider; split_position sets the starting point (0.5).
• Side by Side - A and B laid out next to each other, the honest "just show me both" view.
• Difference - a pixel-difference composite that highlights exactly where the two images diverge. This is the one that tells you whether an upscale actually changed anything beyond resizing.
• Toggle - flips between A and B, useful for quick flick-back-and-forth judgment.

swap flips the roles, and visible A/B labels keep you honest about which side is which. The node resizes its internal preview area with you, so a portrait reference stays readable even when the node is wide.

Inputs and nothing else

• image_a / image_b - optional IMAGE batches. Connect one, or both; if you only care about inspecting one image, connecting just image_a still works as a clean viewer.
• mode, split_position, toggle_image (which image shows first in Toggle), swap.

No outputs. That's the design, and it's a feature: the node drops into a graph to inspect an intermediate result without forcing you to route it onward or add a save node just to see it. When you do want the comparison exported or encoded - say, to hand a difference view to a video pipeline - the pack's (Deno) Video Compare has a comparison output for exactly that, and it's the sibling to reach for once you move from stills to clips.

Install and when it's worth it

cd ComfyUI/custom_nodes
git clone https://github.com/Deno2026/comfyui-deno-custom-nodes.git
# restart ComfyUI

No dependencies.

Honest take: this is a lightweight convenience node, and whether it earns its spot depends on how you work. If you habitually drag the same two outputs into the canvas to eyeball them, this saves you the empty-preview-vs-window juggling. The Difference view in particular is underrated - after an upscale, it answers "did anything actually change here?" in one glance, which is exactly the question the community's upscaler debates keep circling. Just remember the tool's own limit: difference masks overstate change on anything involving motion or interpolation, so use the slider for the verdict and the difference view for the map.