The SVG `fill-rule` property

The fill-rule property decides what counts as "inside" when a path or polygon overlaps itself or has holes. Hover/tap/focus the figure to switch from fill-rule:nonzero to fill-rule:evenodd .

clockwise outer path,
clockwise hole (the outer space is +1, the inner square is +2)
clockwise outer path,
counter-clockwise hole (the outer space is +1, the inner square is 0)
counter-clockwise outer path,
clockwise hole (the outer space is -1, the inner square is 0)
counter-clockwise outer path,
counter-clockwise hole (the outer space is -1, the inner square is -2)

The keywords refer to a way of counting how many path segments you have to cross to reach a given point. The determination is affected by the direction of the path: clockwise paths add to the count, counter-clockwise paths subtract from it.

As a result, path segments that loop in opposite directions cancel each other out with either fill-rule. Loops in the same direction cancel each other out for


    evenodd

, but not for


    nonzero

. Which means you can ignore the path direction for evenodd , and just focus on how many paths you cross, alternating inside/outside for each. But be aware: the default value is nonzero .

The SVG fill-rule property

The SVG `fill-rule` property