What are wildcards?

Wildcards are a feature that randomly replaces part of a prompt for each queue run, so you can add variation to generated results.

For example, if you write photo of {red|yellow|blue} flower, one of red / yellow / blue will be selected at execution time.

When you generate many images at once, using the exact same prompt can get repetitive, so this is a simple way to add variety.

Generate images with a random prompt per queue run

ComfyUI text fields (for example, CLIP Text Encode) support wildcard syntax in the {a|b|c} format by default.

wildcard_core.json

  • photo of {red|yellow|blue} flower

    • One option inside {} is selected and expanded into the prompt
    • So you might get photo of red flower or photo of blue flower

Impact-Pack

By default, only the simplest wildcard pattern is available.

If you want to nest wildcards, bias word frequency, or load candidates from text files, Impact-Pack is the standard choice.

Custom node

ImpactWildcardProcessor / Encode

ImpactWildcardProcessor.json
  • Write your wildcard text in the upper field
  • The expanded result is shown in the lower field

ImpactWildcardEncode can also switch LoRA entries as wildcards.

Wildcard syntax (Impact-Pack)

dynamic prompts

This is the most basic form: list candidates inside {}.

  • {a|b|c}

    • One item is selected using |

  • {a|{1|2|3}|c}

    • Nesting is supported

  • {5::red|4::green|7::blue|black}

    • Add n:: in front of each item to bias the probability
    • Larger numbers are selected more often (probabilities are normalized from the total)

Load from a text file

You can prepare a word list separately and call it as a wildcard source.

    1. Location
    • custom_nodes/ComfyUI-Impact-Pack/custom_wildcards
    1. Format

    • Example: color.txt

      red
blue
yellow
    1. Call it
    • Writing __color__ picks one random line from the text file
    • __color__ hair expands to values like red hair / blue hair / yellow hair

  • Subfolders are also supported

    • If you place custom_wildcards/obj/color.txt, call it as __obj/color__

$$ (multi-select)

$$ is syntax for selecting multiple candidates and returning them as one string.

  • {n$$red|blue|yellow}

    • Selects n items from red/blue/yellow
    • Example: {2$$red|blue|yellow} -> red blue / blue yellow

  • {n1-n2$$red|blue|yellow}

    • Selects between n1 and n2 items (count is also random)
    • Example: {1-3$$red|blue|yellow} can be red or red blue yellow

  • {2$$ and $$red|blue|yellow}

    • You can define a delimiter for joining
    • Example: {2$$ and $$red|blue|yellow} -> red and yellow / blue and red