pathLength

The pathLength attribute lets authors specify a total length for the path, in user units. This value is then used to calibrate the browser's distance calculations with those of the author, by scaling all distance computations using the ratio pathLength/(computed value of path length).

This can affect the actual rendered lengths of paths; including text paths, animation paths, and various stroke operations. Basically, all computations that require the length of the path. stroke-dasharray, for example, will assume the start of the path being 0 and the end point the value defined in the pathLength attribute.

Seven elements are using this attribute: <circle>, <ellipse>, <line>, <path>, <polygon>, <polyline>, and <rect>

<svg viewBox="0 0 100 60" xmlns="http://www.w3.org/2000/svg">
  <style>
  path {
    fill: none;
    stroke: black;
    stroke-width: 2;
    stroke-dasharray: 10;
  }
  </style>

  <!-- No pathLength, the real length of the path is used. In that case, 100 user units -->
  <path d="M 0,10 h100"/>
 
  <!-- compute everything like if the path length was 90 user units long -->
  <path d="M 0,20 h100" pathLength="90"/>
 
  <!-- compute everything like if the path length was 50 user units long -->
  <path d="M 0,30 h100" pathLength="50"/>
 
  <!-- compute everything like if the path length was 30 user units long -->
  <path d="M 0,40 h100" pathLength="30"/>
 
  <!-- compute everything like if the path length was 10 user units long -->
  <path d="M 0,50 h100" pathLength="10"/>
</svg>

circle

For <circle>, pathLength lets authors specify a total length for the circle, in user units.

ellipse

For <ellipse>, pathLength lets authors specify a total length for the ellipse, in user units.

line

For <line>, pathLength lets authors specify a total length for the line, in user units.

path

For <path>, pathLength lets authors specify a total length for the path, in user units.

polygon

For <polygon>, pathLength lets authors specify a total length for the shape, in user units.

polyline

For <polyline>, pathLength lets authors specify a total length for the shape, in user units.

rect

For <rect>, pathLength lets authors specify a total length for the rectangle, in user units.

Specification