🔍 Image Comparer

You upscaled a render, changed a seed, or swapped a LoRA, and now you need to actually see the difference - not squint at two previews across the canvas. That's this node. 🔍 Image Comparer is a terminal A/B viewer: you feed it two images and it lets you flip between them by clicking, drawn right on the ComfyUI canvas.

It ships in Orion4D_MetaNode, the pack built around the PyCode Max engine, and it's the "legacy" version in a pair - this one is made for the classic LiteGraph interface, while Image Comparer V2 handles ComfyUI's Nodes 2.0 frontend. If you're still on the default canvas (most people are), this is the one to reach for.

What it's actually for. Comparing an original and its upscale, before and after a grading pass, or two seeds against each other. The community's constant complaint is that "which upscaler" arguments usually turn out to be two people doing different jobs - more pixels vs. more invented detail (the upscaling doc's split). A comparer doesn't settle the debate, but it's how you check the output isn't doing something dumb like rewriting faces or smearing edges.

How it works. The node takes exactly two inputs, image_a and image_b, and has no outputs - it's an output node you drop at the end of a branch. Click the image to toggle between A and B, or use the two little indicator circles underneath. Because it draws directly on the LiteGraph canvas rather than pasting a bitmap, it stays sharp at any zoom level. If your two images are different sizes - the classic case being an upscaled image next to its 1x original - it aligns them to the largest dimension and letterboxes on black, so nothing is cropped out of the comparison.

Where people get burned: they wire it mid-graph expecting an IMAGE to come out the other side. It doesn't, and it won't. It's a preview node, full stop. Also, don't mistake the black bars for a bug - that's the letterbox doing its job when your two inputs aren't the same dimensions.

Install. In ComfyUI Manager, search "Orion4D_MetaNode" and install, or:

cd ComfyUI/custom_nodes
git clone https://github.com/orion4d/Orion4D_MetaNode

Restart ComfyUI. The node appears under the Orion4D_MetaNode/Preview category. Dependencies are light - the pack's requirements list is mostly things ComfyUI already ships (numpy, Pillow, torch, opencv-python); the heavy stuff like scipy and nvidia-ml-py is optional and you don't need any of it for this node.

The one caveat. If you've switched ComfyUI over to Nodes 2.0, this node technically works but two things degrade: clicking the image no longer toggles (use the circles below), and hovering can darken the image because Nodes 2.0's native rendering overlaps the custom draw. That's not a broken install - it's exactly why the author built Image Comparer V2, and that's the node to use there.