Superside Image Comparer

If you've used rgthree's Image Comparer, you know the seductive part: a draggable divider you slide back and forth to see one image give way to the other. This node is the Superside in-house version of that idea, with one honest difference baked in - there's no interactive slider. It stacks two images side by side into a single static output. That's it.

The trade-off is worth explaining because it's a feature, not a cost-cutting afterthought. The rgthree comparer's slider is a frontend JavaScript widget - it only works while you're sitting at the canvas, and it only exists if the original package's frontend is loaded. The Superside equivalent deliberately ships without that JS, which means it behaves the same everywhere: it's a plain node producing a plain image, usable in headless runs, on exported workflows, and in any ComfyUI frontend without a hidden dependency on rgthree's code. If your pack strategy is "zero dependencies on other people's custom nodes," this is how you get a compare tool.

The inputs

There are only three, and two of them are the images:

• image_a / image_b - the two frames. The node resizes them to match and lays them side by side with a small gap.
• gap (default 8, 0–256) - pixels between the two panels. Crank it up if you want a clear visual separator or room to eyeball the seam; leave it small if you want them visually adjacent.

The output is a single IMAGE containing the composite. Save it, preview it, or feed it onward - it's a normal tensor.

How it works

Same unglamorous machinery as the whole utility half of this pack: both inputs get converted to a common size, placed next to each other with your gap between them, and returned as one image. No API key, no model, no network call, nothing that costs money or sends data anywhere. It's a picture of two pictures.

Installing it

It ships with the rest of the Superside nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/Superside/comfyui-superside-nodes
pip install -r requirements.txt

Then restart ComfyUI and find it under the Superside category. That's the whole install - there are no weights to download and no key to paste.

Which compare node should you actually use?

If you're doing interactive A/B work on your own machine and you already use rgthree, keep using the real comparer - the slider genuinely is nicer for that job. If you want a compare that's reproducible in a workflow, survives export, and doesn't drag a frontend dependency around, this is the one. And if you want labeled panels ("BEFORE" / "AFTER" baked into the image), reach for this pack's Superside Image Compare instead - that one draws text footers, which this one deliberately doesn't. Two compare nodes, two jobs, and neither of them costs you a fal credit.