Display Value

Display Value is the smallest honest utility node in the registry. You wire one thing into it, hit run, and it shows you that value as plain text in a read-only box on the node. That's the whole job. No API call, no model download, no hidden dependency - it's a debug probe, the ComfyUI equivalent of print(). The README sells it as a display for primitives, but the code is friendlier than that: throw a dict or a list at it and it'll JSON-serialize the thing for you.

Why you'd reach for it: ComfyUI hides the data flowing between nodes. When a workflow spits out something unexpected - or nothing at all - your options are to guess or to actually look. Display Value lets you see what's really on a wire: the text out of a prompt template, the number from a math node, the path from a filename templater, all without leaving the graph. And because it's flagged as an output node, ComfyUI treats it as a terminal result - it keeps the value in the queue and renders it, which is exactly what you want from a probe. People also habitually park one of these at the end of a dead-end branch to make sure that branch actually runs and produces something visible. When a workflow misbehaves, this is the first node I add.

How it works

Pure Python plus a tiny bit of frontend glue. The value input is typed * - ComfyUI's "anything" - so any single value from any node plugs straight in. ComfyUI passes inputs wrapped in a list, and the node takes the first element. Strings, ints, floats and bools become str(value); None becomes the literal string "None"; everything else goes through json.dumps, with a "could not be serialized" fallback. A small JS extension bundled in the pack then catches the result and drops it into a read-only multiline text widget on the node.

The one input, the one output

• value (required, type *): whatever you want to inspect. It's required, so wire something in - this is a terminal node, it wants to see a value.
• STRING output: the formatted value as text. Most of the time you ignore it, but it means you can feed the formatted string onward - into a text or metadata node - instead of just eyeballing it.

That's the entire surface area. There are no optional inputs and no other outputs.

Gotchas

The preview stays empty until the node actually runs, so if the workflow errors upstream you learn nothing. It formats only the first element of a list - feed it a batch of fifty strings and you'll see string number one. And it will happily json.dumps a giant structure, so don't wire in a multi-megabyte object and expect a tidy box.

Install

This is the pack's secret weapon: zero dependencies, no models, nothing that can break your environment. Via ComfyUI Manager, search "ComfyUI-Display-Value", or the old-fashioned way:

cd ComfyUI/custom_nodes
git clone https://github.com/edelvarden/ComfyUI-Display-Value

then restart ComfyUI. If the preview widget doesn't appear, hard-refresh the browser tab - the display side is a frontend extension, and ComfyUI caches those aggressively.

Is it the fanciest display node out there? No. rgthree's pack and ComfyUI-Custom-Scripts ship show-text nodes with more chrome and options. But this one does one thing with zero moving parts, and it can't drag the rest of your install down with it. For "I just need to see what's on this wire," that's a lot of value for thirty seconds of setup.