Image Compare 🔍

Two IMAGE inputs, A and B, one comparison node. This is the tool for the "did that LoRA actually change anything" question, or "is the upscale better than the original," or "which seed do I actually prefer" - the kind of judgment call that's genuinely hard to make from two separate preview thumbnails sitting in different parts of your screen.

How it works

Feed it two images and it renders them together in its own on-canvas UI rather than just two separate previews stacked side by side by accident. Per the pack's README, it supports side-by-side layout, an overlay mode, and difference highlighting - modes you switch between inside the node itself to see either the raw comparison or specifically where the two images diverge pixel-for-pixel. That last mode is the one that matters most for catching subtle changes a side-by-side glance would miss: a slightly shifted face, a texture that only changed in one corner, a color-grading difference that's easy to miss eyeballing two full images.

The inputs and outputs that matter

• A - the first image.
• B - the second image.

Output is a single images - the composited comparison result, which you can still chain onward (into a Save Image, or into Grid Filler if you're building a page of comparisons) rather than treating this as a dead end.

Installing it

Via ComfyUI Manager: search "iTools" or "ComfyUI-iTools," install, restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/MohammadAboulEla/ComfyUI-iTools

then restart.

Troubleshooting

Comparison view doesn't render, or difference mode is missing. Check whether you're running ComfyUI's newer Node 2.0 (Beta) frontend - this node is explicitly named in the pack's README as one of four not yet compatible with it, alongside Prompt Record, Image Preview, and the Crop node. Switch to the classic node system for full functionality. This is a common failure mode across the ecosystem right now for any pack with rich custom canvas widgets, not something specific to iTools breaking.

A and B look swapped, or you're not sure which is which. There's no label baked into the output beyond the node's own UI - if you're chaining this into something automated (like an overlay burning in "A" or "B"), you'll need to track which source fed which socket yourself; the node doesn't return that as metadata.

Difference highlighting shows changes everywhere, even where you expect none. Two images that look identical to the eye can still differ pixel-for-pixel from tiny compression artifacts, resizing, or format conversion along the way. If you need a genuinely apples-to-apples diff, make sure both images went through the same save/decode path before reaching this node rather than one being a re-loaded JPEG and the other a fresh PNG straight off the VAE.

You actually want to browse several past generations, not just two specific ones. This node is built for a deliberate two-image comparison - if what you want is to step backward through recent output history instead, this pack's Image Preview node, which keeps its own history, is the better fit.