Merge Image Lists (DEPRECATED)

Merge Image Lists does one narrow thing: it takes image lists and concatenates them into a single list. Two lists of five become one list of ten, in the order you connected them. That's the whole job, and it's a job that core ComfyUI now considers done-by-something-else - the node literally shows "Merge Image Lists (DEPRECATED)" in your node menu.

Why it exists, and why it's deprecated

The list machinery in ComfyUI has grown a lot since this node was first sketched out. In the modern core there's a general-purpose Create List node that handles lists of any type - images, strings, numbers - and it does the concatenation job better. That's the official replacement: the deprecation note in the source says this node is superseded by Create List. So if you're building a new workflow, use Create List and don't think twice.

The image-list concept itself is worth understanding even though this particular node is on the way out. Some core nodes output lists instead of a single batched tensor - a load-folder node gives you a list of images, a tile splitter gives you a list of tiles, Rebatch Images gives you a list of regrouped batches. Lists are how ComfyUI represents "several separate things" as opposed to "one stacked tensor," and nodes that produce lists often need a way to combine two lists into one.

What it does, mechanically

The schema is minimal:

• images - a list of IMAGEs to process.
• Output: images - the same list, concatenated.

Under the hood the input is a group-process list input, and when multiple lists are connected they're simply concatenated in connection order. The implementation is close to a no-op because the merging happens at the input-handling level - you're mostly telling the graph "treat these as one list."

When you'd still see it

Two situations, both involving existing graphs rather than new ones:

• Legacy workflows. Plenty of shared workflows were built when this was the standard way to merge lists. It still runs fine - deprecation in ComfyUI core doesn't mean broken, just "don't build on this."
• Learning what the replacement replaces. If you load an old workflow and swap to Create List, you'll see it's the same operation with more type flexibility.

Honest take: for a node this thin, the article is mostly this - it concatenates lists, it's deprecated, use Create List. If you never touch it, you're not missing anything.

Common issues

• It's a list node, not a batch node. It merges lists. If you actually want to stack images into one batched tensor (concatenate along the batch axis of a single IMAGE), that's the Batch Images node (BatchImagesNode), not this one. Mixing the two up is the classic error: a list of tensors and a single stacked tensor are different shapes and wire into different places.
• Order = connection order. The merged list follows the order you wired the inputs. If the output order matters downstream, check which list you connected first.
• Expecting dedupe or dedup semantics. There's none. It concatenates; duplicates stay.

Bottom line

It ships with ComfyUI core, no install, no models. Understand it as the historical answer to "combine two image lists," use Create List for anything new, and if an old workflow hands you one of these, let it be - it still works.