shape-rendering

The shape-rendering CSS property provides hints to the renderer about what tradeoffs to make when rendering shapes like paths, circles, or rectangles. It only has an effect on the <circle>, <ellipse>, <line>, <path>, <polygon>, <polyline>, and <rect> elements. If explicitly declared, the value of the CSS property overrides the any values of the element's shape-rendering attribute.

Syntax

css
shape-rendering: auto;
shape-rendering: crispEdges;
shape-rendering: geometricPrecision;
shape-rendering: optimizeSpeed;

/* Global values */
shape-rendering: inherit;
shape-rendering: initial;
shape-rendering: revert;
shape-rendering: revert-layer;
shape-rendering: unset;

Values

The <length> and <percentage> values denote the horizontal center of the circle or ellipse.

auto

This value directs the user agents to make tradeoffs in order to balance speed, edge crispness, and geometric precision, with geometric precision given more importance than speed and edge crispness.

crispEdges

This value directs the user agent to emphasize edge contrast over geometric precision or rendering speed. The final rendering is likely to skip techniques such as anti-aliasing. It may also adjust line positions and line widths in order to align edges with device pixels.

geometricPrecision

This value directs the user agent to emphasize geometric precision over speed or crisp edges. The final rendering may involve techniques such as anti-aliasing.

optimizeSpeed

This value directs the user agent to emphasize rendering speed over geometric precision or edge crispness. The final rendering is likely to skip techniques such as anti-aliasing.

Formal definition

Initial valueauto
Applies to<circle>, <ellipse>, <line>, <path>, <polygon>, <polyline>, and <rect> elements in an svg
Inheritedno
Computed valueas specified
Animation typediscrete

Formal syntax

shape-rendering = 
  auto                |
  optimizeSpeed       |
  crispEdges          |
  geometricPrecision

Example

To show the different renderings, we create a set of four ellipses of equal size and shape.

html
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 400 120">
  <ellipse cx="50" cy="60" rx="40" ry="60" />
  <ellipse cx="150" cy="60" rx="40" ry="60" />
  <ellipse cx="250" cy="60" rx="40" ry="60" />
  <ellipse cx="350" cy="60" rx="40" ry="60" />
</svg>

We then apply the four values of shape-rendering, one per ellipse.

css
ellipse:nth-of-type(1) {
  shape-rendering: crispEdges;
}
ellipse:nth-of-type(2) {
  shape-rendering: geometricPrecision;
}
ellipse:nth-of-type(3) {
  shape-rendering: optimizeSpeed;
}
ellipse:nth-of-type(4) {
  shape-rendering: auto;
}

The resulting SVG is shown here. The first and third ellipses (counting from left to right) are more likely to show jagged edges, whereas the second should have a smoother appearance. The fourth and last ellipse's appearance will be dictated by the specific tradeoffs made by the user agent you use to view the example.

Specifications

Specification
Scalable Vector Graphics (SVG) 2
# ShapeRendering

Browser compatibility

BCD tables only load in the browser

See also