stroke-opacity

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨March 2020⁩.

The stroke-opacity attribute is a presentation attribute defining the opacity of the paint server (color, gradient, pattern, etc.) applied to the stroke of a shape.

Note: As a presentation attribute, stroke-opacity also has a CSS property counterpart: stroke-opacity. When both are specified, the CSS property takes priority.

You can use this attribute with the following SVG elements:

Example

html,
body,
svg {
  height: 100%;
}

html

<svg viewBox="0 0 40 10" xmlns="http://www.w3.org/2000/svg">
  <!-- Default stroke opacity: 1 -->
  <circle cx="5" cy="5" r="4" stroke="green" />

  <!-- Stroke opacity as a number -->
  <circle cx="15" cy="5" r="4" stroke="green" stroke-opacity="0.7" />

  <!-- Stroke opacity as a percentage -->
  <circle cx="25" cy="5" r="4" stroke="green" stroke-opacity="50%" />

  <!-- Stroke opacity as a CSS property -->
  <circle cx="35" cy="5" r="4" stroke="green" style="stroke-opacity: .3;" />
</svg>

Usage notes

Value	`[0-1]` \| <percentage>
Default value	`1`
Animatable	Yes

It's important to know that the stroke partially covers the fill of a shape, so a stroke with an opacity different than 1 will partially show the fill underneath. To avoid this effect, it is possible to apply a global opacity with the opacity attribute or to put the stroke behind the fill with the paint-order attribute.