CSS Outline

An outline is a line drawn outside the element's border.

CSS Outline

An outline is a line that is drawn around elements, OUTSIDE the borders, to make the element "stand out".

Example:

<!DOCTYPE html>
<html>
<head>
    <style type="text/css">
        .box {
            background-color: #eee;
            outline: 3px solid red;
            border: 3px solid lightgreen;
            padding: 5px 10px;
        }
    </style>
</head>
<body>
<div class="box">This is a div with outline</div>
</body>
</html>  

Output:

CSS has the following outline properties:

CSS Outline Style

The outline-style property specifies the style of the outline, and can have one of the following values:

• dotted - Defines a dotted outline
• dashed - Defines a dashed outline
• solid - Defines a solid outline
• double - Defines a double outline
• groove - Defines a 3D grooved outline
• ridge - Defines a 3D ridged outline
• inset - Defines a 3D inset outline
• outset - Defines a 3D outset outline
• none - Defines no outline
• hidden - Defines a hidden outline

The following example shows the different outline-style values:

p.dotted {
    outline-style: dotted;
}

p.dashed {
    outline-style: dashed;
}

p.solid {
    outline-style: solid;
}

p.double {
    outline-style: double;
}

p.groove {
    outline-style: groove;
}

p.ridge {
    outline-style: ridge;
}

p.inset {
    outline-style: inset;
}

p.outset {
    outline-style: outset;
}

CSS Outline Width

The outline-width property specifies the width of the outline, and can have one of the following values:

• thin (typically 1px)
• medium (typically 3px)
• thick (typically 5px)
• A specific size (in px, pt, cm, em, etc)

The following example shows some outlines with different widths:

p.ex1 {
    border: 1px solid black;
    outline-style: solid;
    outline-color: red;
    outline-width: thin;
}

p.ex2 {
    border: 1px solid black;
    outline-style: solid;
    outline-color: red;
    outline-width: medium;
}

p.ex3 {
    border: 1px solid black;
    outline-style: solid;
    outline-color: red;
    outline-width: thick;
}

p.ex4 {
    border: 1px solid black;
    outline-style: solid;
    outline-color: red;
    outline-width: 4px;
}

CSS Outline Color

The outline-color property is used to set the color of the outline.

The color can be set by:

• name - specify a color name, like "red"
• HEX - specify a hex value, like "#ff0000"
• RGB - specify a RGB value, like "rgb(255,0,0)"
• HSL - specify a HSL value, like "hsl(0, 100%, 50%)"
• invert - performs a color inversion (which ensures that the outline is visible, regardless of color background)

The following example shows some different outlines with different colors. Also notice that these elements also have a thin black border inside the outline:

p.ex1 {
    border: 2px solid black;
    outline-style: solid;
    outline-color: red;
}

p.ex2 {
    border: 2px solid black;
    outline-style: dotted;
    outline-color: blue;
}

p.ex3 {
    border: 2px solid black;
    outline-style: outset;
    outline-color: grey;
}

CSS Outline - Shorthand property

The outline property is a shorthand property for setting the following individual outline properties:

• outline-width
• outline-style (required)
• outline-color

The outline property is specified as one, two, or three values from the list above. The order of the values does not matter.

The following example shows some outlines specified with the shorthand outline property:

p.ex1 {
    outline: dashed;
}

p.ex2 {
    outline: dotted red;
}

p.ex3 {
    outline: 5px solid yellow;
}

p.ex4 {
    outline: thick ridge pink;
}

CSS Outline Offset

The outline-offset property adds space between an outline and the edge/border of an element. The space between an element and its outline is transparent.