Dark Folders

If you've ever stared at an output directory with ten thousand PNGs in it and given up on finding anything, DarkFolders is for you. It doesn't save images itself - it computes a folder name that rolls over once the folder hits a target size, and you hand that name to an image saver that supports a path input, like 'Save Image w/ Metadata' from the comfy-image-saver pack. Date-prefix folders help, sure, but when a single day's batch is a few thousand images you're back to square one. Count-based rollover is the fix.

How it works

Give it a folder_prefix (default batch-) and a folder_size (default 500). Every time it runs, it scans your ComfyUI output directory for folders matching the prefix, counts the files in each, and picks a folder per the selection_method. The output is a STRING path you wire into your saver's path field. The four selection methods:

• Fill Gaps - scan from 0 up and use the first folder under the size limit (reuses empty or partial folders you've cleared out).
• Highest Not Full - find the highest-numbered folder that actually has files; fill it if it has room, otherwise start the next one. The default behavior for the steady-state "batch of 8, size 16" flow.
• New Every Generation - ignore the size entirely; always create a fresh folder.
• Change On Input Change - keep filling the current folder until some change_on_input value changes, then start a new one. The change_on_input socket is typed *, so any signal works - a checkpoint name, a prompt, a seed.

It also quietly ignores folders that match the prefix but aren't numeric (like batch-abc), so stray folders don't crash the scan.

Gotchas worth knowing

The seed input is a dummy. The source is refreshingly honest about this: the node requires a seed it never actually uses, purely so ComfyUI re-evaluates it every batch. Change the seed to force a folder change. That's a hack, but a working one.

Counts are taken at batch start. The docstring admits a batch can overshoot folder_size - if a folder has 14 images and your batch adds 8 at size 16, it's going to 22 before it rolls over. If per-batch overshoot matters to you, size your folders above your batch size.

It needs a saver with a path option. Stock ComfyUI's Save Image doesn't take one. This node's output is meaningless without comfy-image-saver (or equivalent), so budget for that extra install. State for Change On Input Change is persisted to a JSON file in ComfyUI's temp directory, so clearing temp resets it.

Install

Manager → "DarkPrompts", or:

cd ComfyUI/custom_nodes
git clone https://github.com/darkpixel/darkprompts.git

Restart ComfyUI. No models, no pip deps. If you batch heavily, this is quietly one of the most useful organizational tools in the pack - the rest of DarkPrompts makes your prompts varied; this one keeps the results findable.