To design links or create animations of menu buttons, you might need to use underlines. From this article, you’ll learn about several methods of creating a CSS underline: using text-decoration, border-bottom, background-image, box-shadow properties, or even SVG.
CSS Text-Decoration Property
The text-decoration property is the most straightforward way to underline text. The main issue with text-decoration, however, is its lack of customizability. We’ll see more customized examples further in this article.
For now, let’s see how we can use text-decoration for a simple CSS underline.
The text-decoration property is a shorthand property for 3 other properties:
text-decoration-line (required): overline, underline, underline overline, line-through
text-decoration-style: solid, dotted, dashed, wavy, double
text-decoration-color: for example, #ccc, blue, currentColor, or inherit
Here are several examples:
To remove the underline, simply use text-decoration: none.
If you want to add CSS underline on hover only, use these CSS rules:
a { text-decoration: none; }
a:hover { text-decoration: underline; }
An alternative to text-decoration is the border-bottom property. With border-bottom, you can also add a padding. In the example below, the first link is created with the text-decoration property, and the second one with border-bottom:
a:nth-of-type(1) {
color: #32557f;
text-decoration: underline #32557f dashed;
}
a:nth-of-type(2) {
color: #32557f;
text-decoration: none;
border-bottom: 2px dashed #32557f;
padding-bottom: 3px;
}
Now let’s focus on fancier styling of the CSS underline.
Gradient Underline
You can create a gradient underline with background: linear-gradient and some other background properties. Here’s an example:
<p>Sharks are a <a href="#">group of elasmobranch fish</a> characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head.</p>
a::after {
content: "";
display: block;
width: 32px;
padding-top: 3px;
border-bottom: 2px solid #f9dd94;
}
Read more tips on CSS gradients in CSS Gradients: 8 Examples of Usage.
Short Underline
CSS underline can be of any width or height — even shorter than the word or the link. For example, if you need to create a short underline to mark the beginning of a sentence or a title, use the ::after pseudo-element with the border-bottom property:
<p>Sharks are a <a href="#">group of elasmobranch fish</a> characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head.</p>
a::after {
content: "";
display: block;
width: 32px;
padding-top: 3px;
border-bottom: 2px solid #f9dd94;
}
You can also set CSS underline thickness (for example, 2 px) by applying border-bottom: 2px solid #f9dd94;.
Marker-Style Underline
You can create a short skewed underline with the transform property:
h1 {
padding: 30px 0 8px;
position: relative;
}
h1::before {
content: "";
position: absolute;
left: 7%;
bottom: 16px;
width: 150px;
height: 14px;
transform: skew(-12deg) translateX(-50%);
background: rgba(238,111,87,0.5);
z-index: -1;
}
Moreover, you can create a marker-style underline for a long piece of text. Here’s an example inspired by Codepen.io/Ash:
body {
padding: 4rem;
}
.box {
padding: 2rem;
max-width: 14rem;
background-color: #f2f2f2;
border-radius: 4px;
max-width: 50rem;
}
Underline-specific styles:
:root {
/* The intrinsic width of the underline stroke (in pixels). This is
* the same as the height of the cap images. Don't specify the
* units! This is because of some of the calculations we do later on. */
--underline-intrinsic-width: 8;
/* The actual width of the underline stroke we want to render (in pixels).
* You can modify this, and the sizing and positioning should be calculated
* accordingly. Again, Don't specify the units! */
--underline-width: 12;
/* The color used to draw the underline. It should match the color
* used in the cap images... unfortunately we can't modify the SVG
* fill via CSS because it's a background image. */
--underline-color: #f1a1e3;
/* We need to know the width of the cap images so that we
* can position everything on the x axis accordingly. */
--underline-cap-width: 4px;
/* The border is positioned relative to the bottom of the line.
* We can move it upwards a little to create an overlap effect. */
--underline-offset-y: -2px;
/* The padding to add to the x axis. By default, the caps would be
* aligned with the beginning and end of the line. */
--underline-padding-x: 0.12em;
}
.text {
display: inline;
--underline-width-scale: calc(var(--underline-width) / var(--underline-intrinsic-width));
padding: 0 calc(var(--underline-padding-x) + calc(var(--underline-cap-width) * var(--underline-width-scale)));
box-decoration-break: clone;
background-repeat: no-repeat;
color: #32557f;
background-image:
linear-gradient(180deg, var(--underline-color), var(--underline-color)),
var(--cap-image-left),
var(--cap-image-right);
background-position-x:
calc(var(--underline-cap-width) * var(--underline-width-scale)),
0,
100%;
background-position-y: calc(100% - var(--underline-offset-y) * -1);
background-size:
calc(100% - calc(var(--underline-cap-width) * var(--underline-width-scale) * 2)) calc(var(--underline-width) * 1px),
auto calc(var(--underline-width) * 1px),
auto calc(var(--underline-width) * 1px);
font-size: 3rem;
font-weight: bold;
--underline-width: 20;
--underline-offset-y: -2px;
/* The cap images to use that form the left and right shape.*/
--cap-image-left: url(https://files-6lc03kjqt.now.sh/left-2.svg);
--cap-image-right: url(https://files-e7gkh52mq.now.sh/right-2.svg);
}
Using Images as CSS Underline
You can also use actual images (e. g. SVG or PNG) to style CSS underlines. Here are a couple of examples inspired by John D. Jameson’s CodePen.
Star-shaped CSS underline:
body {
line-height: 1.6;
}
p {
background-image: url("https://s3-us-west-2.amazonaws.com/s.cdpn.io/78779/star.svg");
background-position: 0 1.3em;
background-size: 10px 9px;
background-repeat: repeat-x;
}
You can find more underline examples on sharkcoder.com
Top comments (2)
nice, I was looking for something like this
Love it! I tend to forget about using underlines as a way to complement style or improve the UX. I'm already brainstorming ways to use the marker underline.