D2 Preview Image

The stock PreviewImage node shows you a thumbnail and that's kind of it. D2 Preview Image adds the one interaction people actually want - a button that pops the image into a full-screen gallery where you can actually look at it. For a node that's this boring on paper, it's surprisingly easy to miss once you've used it. If you're generating batches and squinting at 256px thumbnails, this is the small upgrade you didn't know you were shopping for.

How it works

Feed it an IMAGE and it previews the way you'd expect - it saves to ComfyUI's temp directory and shows up in the preview area like any other output. The extra bit is the popup_image button. Click it and whatever images are on the node's input open in a full-screen gallery view. Batch of 12 variations? They're all there, and you can flip through them at actual resolution instead of hunting through the output folder.

There's one deliberate design choice worth noting: it only previews, it doesn't save. The write goes to the temp folder, so it won't accumulate cruft in your output directory the way a Save node would. When you want to keep something, swap in D2 Save Image (same pack, same gallery behavior, plus file output and metadata) or just let the KSampler's image output feed a real save node downstream. Preview-only means the pipeline stays clean.

The inputs

It's a two-field node, which is the whole appeal:

• images - the IMAGE tensor to display. One wire, done.
• popup_image - the button. Click it to open the full-screen gallery.

No outputs. It's a terminal node; nothing flows out of it.

Where it fits

Use it as the end of a visual branch while the real data path continues elsewhere - for example, preview the KSampler's IMAGE while the LATENT keeps going to a detail-pass sampler. ComfyUI lets you wire the same image tensor to multiple nodes, so you can have one D2 Preview Image on the "take a look" branch and a D2 Save Image on the "keep it" branch without any conflict. That's the workflow it's genuinely best at: look at everything, save the keepers.

It also plays nicely with the XY Plot family - when a D2 XY Grid Image hands you a finished comparison grid, popping that into this node's full-screen view is the difference between "I can see there's a difference" and "oh, the third column at strength 0.7 is the one."

Installing and troubleshooting

Part of the D2 Nodes ComfyUI pack:

cd ComfyUI/custom_nodes
git clone https://github.com/da2el-ai/D2-nodes-ComfyUI

or search "D2 Nodes ComfyUI" in ComfyUI Manager. No models, no heavy deps.

Realistically there's almost nothing to troubleshoot here - the common "problem" is expecting it to save files, which it won't. If clicking the button does nothing, make sure you're on a recent ComfyUI (the pack requires the V3 schema since v32.0.0). And if you don't see any preview at all, check that the images input is actually connected - an empty input shows an empty gallery, and that's a wire problem, not a node problem.