repeating-radial-gradient()

With each repetition, the positions of the color stops are shifted by a multiple of the dimensions of the basic radial gradient (the distance between the last color stop and the first). Thus, the position of each ending color stop coincides with a starting color stop; if the color values are different, this will result in a sharp visual transition, which can be mitigated by repeating the first color as the last color.

As with any gradient, a repeating radial gradient has no intrinsic dimensions; i.e., it has no natural or preferred size, nor a preferred ratio. Its concrete size will match the size of the element it applies to.

Because <gradient>s belong to the <image> data type, they can only be used where <image>s can be used. For this reason, repeating-radial-gradient() won't work on background-color and other properties that use the <color> data type.

<position>

The position of the gradient, interpreted in the same way as background-position or transform-origin. If unspecified, it defaults to center.

<shape>

The gradient's shape. The value can be circle (meaning that the gradient's shape is a circle with constant radius) or ellipse (meaning that the shape is an axis-aligned ellipse). If unspecified, it defaults to ellipse.

<extent-keyword>

A keyword describing how big the ending shape must be. The possible values are:

Keyword	Description
closest-side	The gradient's ending shape meets the side of the box closest to its center (for circles) or meets both the vertical and horizontal sides closest to the center (for ellipses).
closest-corner	The gradient's ending shape is sized so that it exactly meets the closest corner of the box from its center.
farthest-side	Similar to closest-side, except the ending shape is sized to meet the side of the box farthest from its center (or vertical and horizontal sides).
farthest-corner	The gradient's ending shape is sized so that it exactly meets the farthest corner of the box from its center.

Note: Early implementations of this function included other keywords (cover and contain) as synonyms of the standard farthest-corner and closest-side, respectively. Use the standard keywords only, as some implementations have already dropped those older variants.

<color-stop>

A color-stop's <color> value, followed by an optional stop position (either a <percentage> or a <length> along the gradient's axis). A percentage of 0%, or a length of 0, represents the center of the gradient; the value 100% represents the intersection of the ending shape with the virtual gradient ray. Percentage values in between are linearly positioned on the virtual gradient ray.

<repeating-radial-gradient()> = 
  repeating-radial-gradient( [ <radial-gradient-syntax> ] )  

<radial-gradient-syntax> = 
  [ <radial-shape> || <radial-size> ]? [ at <position> ]? , <color-stop-list>  

<radial-shape> = 
  circle   |
  ellipse  

<radial-size> = 
  <radial-extent>               |
  <length [0,∞]>                |
  <length-percentage [0,∞]>{2}  

<position> = 
  [ left | center | right | top | bottom | <length-percentage> ]  |
  [ left | center | right ] && [ top | center | bottom ]  |
  [ left | center | right | <length-percentage> ] [ top | center | bottom | <length-percentage> ]  |
  [ [ left | right ] <length-percentage> ] && [ [ top | bottom ] <length-percentage> ]  

<color-stop-list> = 
  <linear-color-stop> , [ <linear-color-hint>? , <linear-color-stop> ]#?  

<radial-extent> = 
  closest-corner   |
  closest-side     |
  farthest-corner  |
  farthest-side    

<length-percentage> = 
  <length>      |
  <percentage>  

<linear-color-stop> = 
  <color> <length-percentage>?  

<linear-color-hint> = 
  <length-percentage>  

<div class="radial-gradient"></div>

.radial-gradient {
  width: 240px;
  height: 120px;
}

.radial-gradient {
  background: repeating-radial-gradient(
    ellipse farthest-corner at 20% 20%,
    red,
    black 5%,
    blue 5%,
    green 10%
  );
  background: repeating-radial-gradient(
    ellipse farthest-corner at 20% 20%,
    red 0 5%,
    green 5% 10%
  );
}

The elliptical gradient will be centered 20% from the top left, and will repeat 10 times between the center and the farthest corner (the bottom right corner). Browsers supporting multi position color stops will display a red and green striped ellipse. Browsers not supporting the syntax yet will see a gradient that goes from red to black and then from blue to green.

<div class="shorter"></div>
<div class="longer"></div>

div {
  display: inline-block;
  margin-top: 1rem;
  width: 45vw;
  height: 80vh;
}

.shorter::before {
  content: "shorter hue";
  display: block;
  margin-top: -1rem;
}

.longer::before {
  content: "longer hue";
  display: block;
  margin-top: -1rem;
}

In this example for interpolation, hsl color system is being used and hue is being interpolated.

.shorter {
  background-image: repeating-radial-gradient(
    circle at center in hsl shorter hue,
    red 30px,
    blue 60px
  );
}

.longer {
  background-image: repeating-radial-gradient(
    circle at center in hsl longer hue,
    red 30px,
    blue 60px
  );
}

The box on the left uses shorter interpolation, meaning the color goes from red to blue using the shorter arc on color wheel. The box on the right uses longer interpolation, meaning the color goes from red to blue using the longer arc, traversing through greens, yellows, and oranges.

• Using CSS gradients
• Other gradient functions: radial-gradient(), linear-gradient(), repeating-linear-gradient(), conic-gradient(), repeating-conic-gradient()
• <hue-interpolation-method>
• <color-interpolation-method>
• <image>
• image()
• element()
• image-set()
• cross-fade()