flood-opacity

An SVG property that sets the transparency level of an SVG filter's flood color. 0 is invisible, 1 is fully solid.

It is documented as part of the Filter Effects specification.

/* Usage Example */
feFlood {
  /* Sets the opacity of the flood area */
  flood-opacity: 0.8;
}

/* Syntax */
flood-opacity: opacity;

/* Global values */
flood-opacity: inherit;
flood-opacity: initial;
flood-opacity: revert;
flood-opacity: revert-layer;
flood-opacity: unset;
Widely available Since 2015 96% global usage

This feature is well established and works across many devices and browser versions. It has been available across browsers since 2015.

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