marker-start

Baseline Widely available

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

The marker-start CSS property points to a marker that will be drawn on the first vertex of the element's path; that is, at its starting vertex. The marker must have been defined using an SVG <marker> element, and can only be referenced with a <url> value. The value of the CSS property overrides any values of the marker-start attribute in the SVG.

For many marker-supporting shapes, the first and last vertices are in the same place: for example, the top left corner of a <rect>. In such shapes, if both the first and last markers are defined, two markers will be drawn at that point, though they may not point in the same direction.

Note: The marker-start property will only have an effect for elements that can use SVG markers. See marker-start for a list.

Syntax

css

marker-start: none;
marker-start: url(markers.svg#arrow);

/* Global values */
marker-start: inherit;
marker-start: initial;
marker-start: revert;
marker-start: revert-layer;
marker-start: unset;

Values

none: This means no marker will be drawn at the first vertex of the element's path.
<marker-ref>: A <url> that refers to a marker defined by an SVG <marker> element, to be drawn at the first vertex of the element's path. If the URL reference is invalid, no marker will be drawn at the path's first vertex.

Formal definition

Initial value	`none`
Applies to	`<circle>`, `<ellipse>`, `<line>`, `<path>`, `<polygon>`, `<polyline>`, and `<rect>` elements in an `svg`
Inherited	yes
Computed value	as specified, but with `<url>` values made absolute
Animation type	discrete

Formal syntax

marker-start = 
  none          |
  <marker-ref>  

<marker-ref> = 
  <url>  

<url> = 
  <url()>  |
  <src()>  

<url()> = 
  url( <string> <url-modifier>* )  |
  <url-token>                      

<src()> = 
  src( <string> <url-modifier>* )

Example

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

html

<svg viewBox="0 0 120 120" xmlns="http://www.w3.org/2000/svg">
  <defs>
    <marker
      id="triangle"
      viewBox="0 0 10 10"
      markerWidth="10"
      markerHeight="10"
      refX="1"
      refY="5"
      markerUnits="strokeWidth"
      orient="auto">
      <path d="M 0 0 L 10 5 L 0 10 z" fill="#f00" />
    </marker>
  </defs>
  <polyline
    id="test"
    fill="none"
    stroke="black"
    points="20,100 40,60 70,80 100,20" />
</svg>

css

polyline#test {
  marker-start: url(#triangle);
}

Specifications

Specification
Scalable Vector Graphics (SVG) 2 # VertexMarkerProperties

Browser compatibility

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