Image Compare Pixaroma

The most common ComfyUI question nobody asks out loud is "did that actually change anything?" You upscale, you inpaint, you swap a checkpoint, and the only way to know if it got better is comparing the two images - which means two preview nodes, two tabs, and a lot of eye-switching. Image Compare Pixaroma is a single terminal node that shows both at once with an honest set of comparison tools. Wire any two IMAGE outputs into image1 and image2, run once, and you get three ways to look at them.

How it works

The on-node viewer has three modes:

• Side-by-side with a slider - drag the divider back and forth across the pair. The standard way to spot-region differences, and the mode most people default to.
• Overlap with adjustable opacity - one image over the other so you can fade between them and watch a region morph.
• Diff - highlights exactly what changed between the two versions. This is the one that catches subtle shifts (a recolor that drifted, a face detail that moved) that your eye will happily gloss over side by side.

Both inputs are optional, and that's a feature, not an edge case. If one branch feeding an input is muted or bypassed - common in a workflow that toggles between txt2img and img2img - the node just shows the image that is connected instead of throwing a system error. Neither connected? A short "connect images" note. It never interrupts a run, so it's safe to leave permanently parked in the graph. There are no outputs; it's a pure viewer, wired at the end of a branch like a Preview node. Each input also shows its resolution, turning orange when the two don't match - a quiet hint when your "identical" images are actually different sizes.

Where it fits

The obvious use is a before/after: original vs upscaled, pre-inpaint vs post-inpaint. It also shines for A/B-ing: two checkpoint variants, two prompt versions, two denoise strengths - wire both into Compare instead of running them into the same preview and hoping you remember which was which. The pack's Inpaint Stitch even hands back the untouched original specifically so you can drop both it and the result into Compare for an instant diff. The default mode is configurable under Settings → Pixaroma → Compare if you prefer starting in diff view.

Install

It's part of the Pixaroma pack:

cd ComfyUI/custom_nodes
git clone https://github.com/pixaroma/ComfyUI-Pixaroma

or ComfyUI Manager → Pixaroma → install, restart. No extra dependencies. One tip from the changelog: a past bug where a missing image crashed the node was fixed so both inputs are now genuinely optional - if you're on an old version and hitting that, update the pack and hard-refresh the browser (Ctrl+Shift+R) rather than debugging your graph.