Image Compare (Inteliweb)

Comparing two generations side by side is the single most useful debugging habit in ComfyUI, and it's one of the things rgthree's Image Comparer made famous - so famous that when Nodes 2.0 broke it, the top reply in the thread was someone who used it on "almost every workflow." Image Compare (Inteliweb) is the same idea: feed it two IMAGEs and it shows them in one interactive viewer with a draggable divider, so you can flip between "before" and "after" on a hires-fix, a different sampler, a stronger LoRA - without swapping images in an external viewer.

How it works

It's an output node with no outputs, and it deliberately dodges ComfyUI's stock preview widget. The backend saves each image to ComfyUI's temp directory and returns them under a custom inteliweb_compare UI key, which stops the frontend from stacking its own permanent Preview Image widget underneath. The frontend then draws the comparison canvas with four view modes: Left Right, Up Down, Toggle, and Side by Side. The split views let you drag the divider to check a specific area at full detail - the way you actually notice a difference, rather than squinting at two flat thumbnails.

The inputs

Just two, both optional:

• image_a - first image.
• image_b - second image.

One small gotcha: it compares the first frame of each batch. If you feed it a batch of multiple images, only tensor[0] gets previewed per slot, so don't expect a per-frame comparison grid. For two single generations it's exactly right.

Installing it

It comes with the Inteliweb pack, so the install is one-time and shared:

cd ComfyUI/custom_nodes
git clone https://github.com/maoper11/comfyui_inteliweb_nodes.git
cd comfyui_inteliweb_nodes
python -m pip install -r requirements.txt

ComfyUI Manager also has it ("ComfyUI_Inteliweb_nodes"). Dependencies are minimal - psutil and nvidia-ml-py - no model downloads, then restart ComfyUI.

Why you might prefer it

The headline feature is the one rgthree's comparer lost: it explicitly works on both Classic and Nodes 2.0, even mid-session when you switch renderers. That's a deliberate compatibility commitment from this pack's author (the changelog tracks Nodes 2.0 fixes for this node across multiple releases), and it's worth a lot if you're on the new frontend. The v0.20.4 update also made the viewer adopt your node's body color and replaced the old mode dropdown with compact icons, which sounds cosmetic until you're staring at a bright white viewer in a dark theme for the tenth hour.

The honest trade-off: if you're on Classic and happy with rgthree, there's no strong reason to switch - the core idea is identical. But if Nodes 2.0 is your life, or you want a comparer that stays out of your way, this one works where the old standby doesn't.