Concatenate String

Not every node in ComfyUI_ezXY is about plotting - Concatenate String is the plain text-joining utility the rest of the pack (and honestly any workflow) reaches for when you need to build a string out of parts instead of typing it once. Think building a label from a value plus a unit, or stitching a prefix onto a filename per grid cell.

How it works

Two multiline string inputs and a separator between them: string_1 + separator + string_2, output as one Joined String. That's it - no formatting, no conditionals, just concatenation. In an ezXY workflow it's commonly the last step before String to Label: pull a value out of Number from List, turn it into text, and glue a label like "cfg: " in front of it before rendering it as an image label.

Inputs and outputs

• string_1 and string_2 - multiline text fields, either can also take a wired string input from another node.
• separator - what goes between them. Leave it empty for a straight concatenation, or use a space, comma, colon - whatever your label needs.
• Joined String - the result, a single string.

Installing ComfyUI_ezXY

Via ComfyUI Manager: search "ComfyUI_ezXY", install, restart. Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/GMapeSplat/ComfyUI_ezXY.git

No models, no extra dependencies to install - this node in particular is about as lightweight as custom nodes get.

Common issues & troubleshooting

There's genuinely not much that breaks about a string concatenation node - it's the simplest thing in the pack. The failure mode people actually hit is upstream of it: if you're feeding it a value from Number from List or ezMath, remember those are numeric outputs, and whether a FLOAT wires straight into a STRING-typed input depends on ComfyUI_ezXY's "automatic type-casting" feature (the autoCastPatch.py runtime patch mentioned in the README), which exists specifically to paper over that kind of int/float/string mismatch. If a wire that should connect refuses to, or throws instead of casting, that patch is the thing to look at, and it's toggleable in config.yaml if you want to rule it out.

Beyond that, the pack-wide caveat still applies: the README says outright it doesn't work with the current version of ComfyUI, and the project has visible signs of being under-maintained (a stranded user in 2025 asking to fork a node out because the repo was broken). Concatenate String is simple enough that it's the least likely node here to be affected, but if your whole custom_nodes folder throws import errors on startup, that's a pack-level issue, not this node specifically.