repeating-radial-gradient property - CSS Reference

Definition and Usage

This works similarly to the standard radial gradients as described by radial-gradient, but it automatically repeats the color stops infinitely in both directions, with their positions shifted by multiples of the difference between the last color stop's position and the first one's position.

Like any other gradient, a repeating CSS radial gradient is not a CSS <color> but an image with no intrinsic dimensions; that is, it has no natural or preferred size, nor ratio. Its concrete size will match the one of the element it applies to.

Mozilla currently only supports CSS gradients as values of the background-image property, as well as within the shorthand background. You specify a gradient value instead of an image URL.

Syntax

Formal grammar:
  repeating-radial-gradient( [[ circle      || <length> ]                                 [ at <position> ]? , |
                              [ ellipse                || [<length> | <percentage> ]{2}] [ at <position> ]? , |
                              [ [ circle | ellipse ] || <extent-keyword> ]                   [ at <position> ]? , |
                                                                                                      at <position> ,     <color-stop> [ , <color-stop> ]+ )
                            \--------------------------------------------------------------------------------------/\-----------------------------/
                                   Definition of the contour, size and position of the ending shape                      List of color stops
              where <extent-keyword> = closest-corner | closest-side | farthest-corner | farthest-side
                    and <color-stop> = <color> [ <percentage> | <length> ]?

Definition of the ending shape
repeating-radial-gradient( circle, … )                /* Synonym of repeating-radial-gradient( circle farthest-corner, …) */
repeating-radial-gradient( ellipse, … )               /* Synonym of repeating-radial-gradient( ellipse farthest-corner, …) */
repeating-radial-gradient( <extent-keyword>, … )      /* It draws concentric circles */
repeating-radial-gradient( circle radius, … )         /* Concentrinc centered circles of the given length. It can't be in %. */
repeating-radial-gradient( ellipse x-axis y-axis, … ) /* The two semi-major axis are given, horizontal, then vertical */
Definition of the position of the shape
repeating-radial-gradient (… at <position>, … )
Definition of the color stops
repeating-radial-gradient (…, <color-stop>)
repeating-radial-gradient (…, <color-stop>, <color-stop>)

Values

<position>

A <position>, interpreted in the same way as background-position or transform-origin. If omitted, the default is center.

<angle>

An angle establishing the gradient line, which extends from the starting point at this angle; this is 0deg by default.

<shape>

The gradient's shape. This is one of circle (meaning that the gradient's shape is a circle with constant radius) or ellipse (meaning that the shape is an axis-aligned ellipse). The default value is ellipse.

<size>

The size of the gradient. This is one of the Size constants listed below.

<color-stop>

Representing a fixed color at a precise position, this value is composed by a <color> value, followed by an optional stop position (either a <percentage> or a <length> along the virtual gradient ray). A percentage of 0%, or a length of 0, represents the center of the gradient, the value 100% the intersection of the ending shape with the virtual gradient ray. Percentage values in-between. are linearily positioned on the gradient ray.

<extent-keyword>

Are keywords describing how big the ending shape must be. The possible keywords are:

Constant	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 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 it exactly meets the farthest corner of the box from its center.

Early drafts were defining to other keywords, cover and contain, synonyms of the standard farthest-corner and closest-side respectively. Do exclusively use the standard keyword as some implementations have dropped to older variants.

Size constants

Constant	Description
closest-side	The gradient's 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 shape is sized so it exactly meets the closest corner of the box from its center.
farthest-side	Similar to closest-side, except the shape is sized to meet the side of the box farthest from its center (or vertical and horizontal sides).
farthest-corner	The gradient's shape is sized so it exactly meets the farthest corner of the box from its center.
contain	A synonym for closest-side.
cover	A synonym for farthest-corner.

Examples

Radial gradients also run along an axis. At each end point of the axis, a radius is specified. This can be imagined as creating two "circles", where for each circle the center is specified by the point and the radius is specified by the radius length. The gradient runs outwards from the circumference of the inner circle to the circumference of the outer circle.

background: repeating-radial-gradient(black, black 5px, white 5px, white 10px); /* Black & white */
background: repeating-radial-gradient(ellipse farthest-corner, red, black 5%, blue 5%, green 10%); /* Farthest-corner */