Append Strings To List

This is one of those tiny plumbing nodes that only makes sense once you understand ComfyUI's "list" concept, so let's start there. Most nodes in ComfyUI process one thing at a time. But ComfyUI also has a mode where a single output can carry a list of values, and when a downstream node receives a list it runs once per item automatically. That's how you get a batch of prompts, a batch of settings, a sweep. AppendStringsToList exists to help you assemble one of those string lists by hand.

It ships in kijai's KJNodes, the utility-heavy pack that's on more machines than almost any other. Nothing here is glamorous, but this is the kind of node that quietly unblocks a batch workflow.

How it works

You give it two strings and it hands back a list containing both, in order. The name says "append," and the real value shows up when you chain these: the output of one AppendStringsToList feeds into the next, and each stop adds another entry, so you grow a list of arbitrary length by daisy-chaining. It's the manual, visual way to construct a small string list without writing any code or wrangling a spreadsheet node.

Where you'd reach for it: feeding a handful of distinct prompts into an encoder that then runs your sampler once per prompt, or assembling a set of filename suffixes, tags, or wildcards you want iterated over in a single queued run.

The inputs and outputs that matter

There's not much surface here, which is the point:

• string1 and string2 - the two strings to combine into the list. Both default to empty. Type them in directly, or wire text in from other nodes.

The output is a single STRING slot, but it carries a list of the two values rather than one concatenated blob. That distinction matters: this does not glue "cat" and "dog" into "catdog". It produces the two-item list ["cat", "dog"], and whatever you connect it to will process each item separately. If what you actually wanted was to join two strings into one, this is the wrong node, you want a concatenate/combine node instead.

Installing it

Odds are you already have KJNodes. If not, grab it through ComfyUI Manager by searching KJNodes for ComfyUI, install, and restart. Manual route:

cd ComfyUI/custom_nodes
git clone https://github.com/kijai/ComfyUI-KJNodes
pip install -r ComfyUI-KJNodes/requirements.txt

Restart ComfyUI afterward. No models, no heavy dependencies for this one.

Common issues

"It's concatenating my strings into gibberish." It isn't, actually. It's building a two-item list and the node you fed it into is iterating over it, which can look like scrambled output if you expected a single value. If you truly want one merged string, use a string-concatenate node, not this.

Downstream node only runs once. Whatever receives the list has to support list processing for the per-item behavior to kick in. Most text-consuming nodes do, but if yours collapses the list, that's a limitation on the receiving end, not here.

I need more than two entries. Chain them. The output of one feeds the string1 (or string2) input of the next, and each node in the chain adds an item. It's a bit fiddly past three or four, at which point a dedicated batch/wildcard node is usually the cleaner tool.