Join Image Lists

Join Image Lists takes up to five lists of images and concatenates them into one, in order. In1 and In2 are required; In3, In4, In5 are optional and can stay unwired. The output is a single Joined image list - plus a Sizes output that's quietly the most useful part of the node.

The Sizes output is a list of integers reporting how long each input list was: feed in lists of 4, 6, and 2 images and Sizes returns [4, 6, 2], with Joined containing all 12 in that order. That's not a bonus - it's the node giving you the exact information you need to split things back apart later. ComfyUI's grid tools work on flat lists, so if you merge three folders of renders into one list and then feed that into a grid assembler, Sizes is what tells the assembler where folder A ends and folder B begins. The sibling node Join Float Lists doesn't offer this; the image and any-type joins do, because re-slicing images is a real workflow step.

The realistic use case: you have renders spread across two or three folders (different seeds, different prompts, different runs) and you want them all in one grid. Two Image List Loaders plus this node gives you one combined list, and the Sizes output flows straight into the split logic of XYImage or its deprecated predecessor. It's the natural companion to the pack's loader, and the pairing is where the pack's list philosophy clicks: load in pieces, join, slice by the sizes you were told.

It's list-aware on every input, so single images are treated as one-element lists, and unwired optional inputs are simply skipped - no phantom empties. There's no list-length validation here; the node will happily concatenate whatever lengths you give it, which is why the Sizes output matters more than it looks. If the joined order ever seems wrong, Sizes is your audit trail.

One honest note: with up to five inputs it overlaps with the generic Join List Any (Kep_JoinListAny), which joins any type. The difference is this node is typed IMAGE and carries the Sizes output; the any-type one is untyped and doesn't tell you sizes. If you're working with images, use this one.

Install is the standard pack procedure with no extra dependencies:

cd ComfyUI/custom_nodes
git clone https://github.com/M1kep/Comfy_KepListStuff

Restart ComfyUI or install Comfy_KepListStuff via Manager, then find it under List Stuff. Merge your folders, read your sizes, and grid on.