CSS text-decoration-thickness Property
Example
Set different thickness of the decoration line for <h1>, <h2>, <h3>, and <h4> elements:
  h1 {
  text-decoration: underline;
  
  text-decoration-thickness: auto; 
}
  
h2 {
  text-decoration: underline;
  
  text-decoration-thickness: 5px; 
}
h3 {
  text-decoration: underline;
  
  text-decoration-thickness: 50%; 
}
/* Use shorthand property */
h4 {
  text-decoration: 
  underline solid red 50%;
}
Try it Yourself »
Definition and Usage
The text-decoration-thickness property specifies the 
thickness of the decoration line.
| Default value: | auto | 
|---|---|
| Inherited: | no | 
| Animatable: | no, see individual properties. Read about animatable | 
| Version: | CSS4 | 
| JavaScript syntax: | object.style.textDecorationThickness="5px" Try it | 
Browser Support
The numbers in the table specify the first browser version that fully supports the property.
| Property | |||||
|---|---|---|---|---|---|
| text-decoration-thickness | 89.0 | 89.0 | 70.0 | 12.1 | 75.0 | 
CSS Syntax
text-decoration-thickness: 
  auto|from-font|length/percentage|initial|inherit;
Property Values
| Value | Description | 
|---|---|
| auto | The browser chooses the thickness of the decoration line | 
| from-font | If a font file contains information about a preferred thickness, use that value. If not, behave as auto | 
| length/percentage | Specifies the thickness as a length or % | 
| initial | Sets this property to its default value. Read about initial | 
| inherit | Inherits this property from its parent element. Read about inherit | 
Related Pages
CSS reference: text-decoration property
CSS tutorial: CSS Text Decoration