Command line

npx unstroke icons/ -o outlined/                 # a whole folder, tree mirrored
npx unstroke icon.svg > icon-outline.svg         # single file to stdout
npx unstroke icons/*.svg --write                 # in place
npx unstroke icons/ -o thin/ --stroke-width 1.5  # every weight from one source
npx unstroke icons/ -o out/ --optimize           # plus SVGO (needs the svgo package)

unstroke --help lists every flag. They mirror the API options one to one: --tolerance, --linecap, --no-curves, --precision and so on.

Unsupported input

When a file uses something the outline can't reproduce, such as a dashed stroke, a <text> element, markers, a clip path, partial opacity or several colours, the CLI converts it anyway and prints a warning on stderr:

icons/dashed.svg: warning: stroke-dasharray on <path> is ignored, the stroke is outlined as a solid line
12 of 12 files converted in 0.1s, 1 with warnings

In a build I'd rather have that fail, so there's --strict. It treats every such file as an error, skips it and exits with code 1 once the rest is done:

npx unstroke icons/ -o outlined/ --strict

The options reference lists every warning and what it means. -q hides the progress line but not the warnings.