CSS ellipse() Function
ellipse() function is a CSS basic shape value that's part of the CSS Shapes module.
Basic shapes such as
ellipse() can be used as a value for properties such as
shape-outside to control the flow of content around the element, and
clip-path to clip the element's contents to the basic shape.
This means you can do things like, have text flowing around the element in the shape of an ellipse, have an image clipped to the shape of an ellipse, etc.
Here's an example of how the
ellipse() function works with the
Here we have a
div floated to the left. And because I've applied
shape-outside: ellipse() to it, the subsequent text flows around the (invisible) ellipse that I specified.
It's easier to visualize this concept by looking at the following example.
As you can see, the ellipse is drawn within the floated box. The floated box actually protrudes out from the ellipse, into the surrounding text. But because we've applied
shape-outside: ellipse(), the text is allowed to flow right up to the edges of the ellipse. The extent to which it does this depends on any arguments that you pass to the
This example doesn't use any arguments to specify the ellipse's radii. Therefore, it uses the default value, which is
closest-side closest-side (ellipses use two values here).
How to Specify the Ellipse's Radii
You can specify the radii of the ellipse by providing two arguments to the
ellipse() function. The arguments specify the x-axis and y-axis radii of the ellipse, in that order.
closest-side is the default value for both radii. So it's the equivalent as doing this:
closest-side means that the radius will be based on the length from the center of the shape to the closest side of the reference box (in the radius dimension).
You can also specify
farthest-side. In this case, the ellipse will base the radius on the length from the center of the shape to the farthest side of the reference box (in the radius dimension).
Here's an example of using a percentage value.
How to Position the Ellipse
You can specify a position for the ellipse by following the radii arguments with a valid CSS position. This position specifies the ellipse's center. Just separate the radius and the position with
at. Like this:
The center of this ellipse is 10 pixels from the left and 150 pixels from the top.
Here's a working example:
Position can be represented as a length value, a percentage value, or a combination of the
Here's an example of using the CSS
ellipse() function with the
If your browser supports the
clip-path property (and the
ellipse() function), the above image should appear in the shape of an ellipse. Otherwise it will appear as a normal rectangle shape.
Here's another example, this time with some arguments that change the ellipse's radii and position:
At the time of writing, browser support for the
clip-path property is limited. None of the major browsers support it, however, webkit browsers have partial support using the
The official syntax of the
ellipse() function is as follows:
And the syntax of
The default value is
The syntax for
The following values can be used to specify the ellipse's radii:
This can be specified in either of the following ways:
- Specifies a length value to use (e.g.
vw, etc) for the radius.
- Specifies a percentage value to use. The percentage value uses the width and height of the reference box.
This is the default value.
Specifies that the ellipse's radius will use the length from the center of the shape to the closest side of the box that uses the
ellipse()function (this is the closest side in the radius dimension).
Specifies that the ellipse's radius will use the length from the center of the shape to the farthest side of the reference box (the farthest side in the radius dimension).
The position argument defines the center of the circle. It is specified as a value from the top, left corner of the reference box using the values listed above (under Official Syntax).
ellipse()function is defined in CSS Shapes Module Level 1 (W3C Candidate Recommendation, 20 March 2014)
- It's also being further defined in CSS Shapes Module Level 2 (Editorâ€™s Draft)
The following table provided by Caniuse.com shows the level of browser support for this feature.