Today's article we will go into learning how to create as well as design the default underline in the website into beautiful underlined lines to attracting users' attention!
CSS Underline Examples
Collection of CSS Underline Effects

You can check out the results below.
See the Pen Cool CSS Underline Effects by Jordan Marshall (@TheCSSKing) on CodePen.
Stylish Underline CSS

You can check out the results below.
See the Pen Underlines 7: background-image (External) by John D. Jameson (@johndjameson) on CodePen.
CSS Underline Box-Shadow

You can check out the results below.
See the Pen Underlines 5: box-shadow by John D. Jameson (@johndjameson) on CodePen.
CSS Underline Thickness

You can check out the results below.
See the Pen Nice SCSS typography underline by MrPirrera (@pirrera) on CodePen.
Underline Gradient Animation CSS3
You can check out the results below.
See the Pen Underline gradient animation by NickNoordijk (@NickNoordijk) on CodePen.
SVG Text Underline

You can check out the results below.
See the Pen SVG Text Underline by Andrew Spencer (@iam_aspencer) on CodePen.
CSS Underline Color

You can check out the results below.
See the Pen A Better underline by Matt Gross (@mattgrosswork) on CodePen.
Hover Underline Effect CSS

You can check out the results below.
See the Pen underline effect by Bogdan Blinnikov (@bonkalol) on CodePen.
Javascript Underline Effects

You can check out the results below.
See the Pen Rough Notation by Chris Coyier (@chriscoyier) on CodePen.
Underline Animation CSS3

You can check out the results below.
See the Pen Guitar String Link Underlines by James Almeida (@jimmyplaysdrums) on CodePen.
Underline Effect With SVG

You can check out the results below.
See the Pen Bendy underline effect with SVG by Rachel Smith (@rachsmith) on CodePen.
Hover Underline HTML5 CSS3

You can check out the results below.
See the Pen Cool CSS Underline by timaronan (@timaronan) on CodePen.
CSS Underline Gradient Color

You can check out the results below.
See the Pen CSS Underline by iLord (@iLord) on CodePen.
CSS Animate Underline Multiline

You can check out the results below.
See the Pen How do I get a custom colored underline that will span multiple lines? by Will King (@Wking) on CodePen.
Hover Underline CSS

You can check out the results below.
See the Pen Sass mixin library for text hover by Antonija Šimić (@tonkec) on CodePen.
Animated Underline Hover

You can check out the results below.
See the Pen Animated CSS Underline Hover Examples by msco195 (@msco195) on CodePen.
Simple CSS Sliding Underline Menu

You can check out the results below.
See the Pen Simple CSS Sliding Underline Menu by Ryan Morse (@rm) on CodePen.
Underline animation

You can check out the results below.
See the Pen Underline animation by Aaron Iker (@aaroniker) on CodePen.
Animated underline effect on several lines

You can check out the results below.
See the Pen Animated underline effect on several lines by cecile (@cecilehabran) on CodePen.
Multi-line spanning animated underline

You can check out the results below.
See the Pen Multi-line spanning animated underline. by Cassie Evans (@cassie-codes) on CodePen.
Text decoration underline animated

You can check out the results below.
See the Pen text-decoration: underline animated by Kseso (@Kseso) on CodePen.
Animate underline wavy

You can check out the results below.
See the Pen Animate underline wavy by David Darnes (@daviddarnes) on CodePen.
Text underline hover effects

You can check out the results below.
See the Pen Text underline hover effects by Misha Heesakkers (@MishaHahaha) on CodePen.
Multi-line animated underline text effects

You can check out the results below.
See the Pen Multi-line animated underline text effects by Stas Melnikov (@melnik909) on CodePen.
CSS Underline On Hover

You can check out the results below.
See the Pen CSS Underline -> Button by Bobby Showalter (@bobbyshowalter) on CodePen.
Summary
I hope the article will provide you with useful underline settings for web development, and if you have any questions, just send an email and I will respond as soon as possible. I hope you continue to support the site so that I can write more good articles. Have a nice day!