Ultimate Concat (Mobile)

ComfyUI's default text handling is basic: Text nodes in, one string out. When you're assembling a prompt from parts - a base, a character, some style tags, a quality line - you end up with a chain of Text Concat nodes that's impossible to read. Ultimate Concat (Mobile) is the version that stays readable: up to 24 labeled prefix/value pairs, and only the ones you actually fill in get joined.

How it works

Every slot has two parts: a prefix_i text widget (the label or fixed content) and a value_i input of type * that accepts a wire from anything - another STRING, an INT from a math node, a filename, whatever you've got. A small JS helper in the pack hides the slots you're not using based on concat_count, and renames each value input to match its prefix, so the node reads like a labeled form instead of a wall of fields.

When it runs, for each active slot, if the prefix is non-empty the node appends prefix + value + delimiter. Slots with an empty prefix are skipped entirely.

The behavior that matters

The one thing that trips people up: delimiter is a suffix, not a separator. Joining "a", "b", "c" with , gives you a,b,c, - trailing comma included. Plan your delimiter accordingly.

Two nicer details, both straight from the code:

• Type the literal \n (backslash-n) as the delimiter and it becomes a real newline - handy for multi-line prompts.
• value_i inputs are * typed, so you can pull in numbers or text computed by other nodes instead of hand-typing everything.

Output

One STRING output, named "Concat String". Wire it into a CLIPTextEncode's text input for prompt assembly, or into anything else that eats a string.

The small trap

concat_count claims a range of 1–25, but there are only 24 prefix/value slots. Set it to 25 and the 25th position evaluates to a literal NoneNone that gets appended to your string. Easy to avoid once you know; mildly confusing until you do.

Install and caveats

It's part of the same early-stage pack from Soze Inc (ComfyUI-Mobile). ComfyUI Manager, search "ComfyUI-Mobile", or:

cd ComfyUI/custom_nodes
git clone https://github.com/SozeInc/ComfyUI-Mobile

Then restart. requests is the only dependency, and there are no models to download. The pack README admits it's under active development and "not functional as a stand alone install", but this is the most self-contained node of the three: no external binary, no flow control, just string assembly.

Honestly, this is the one node in the pack I'd reach for. If you build prompts from modular parts - or want to pipe a value from another node into your prompt without copy-pasting - it does the job cleanly.