In HTML 4.01, the <u> element was used to specify an underlined text. But the usage of HTML for stylistic effects isn’t a good practice anymore. Instead, it should be used for adding structure and semantic meaning.

In HTML5, the <u> element has a new, semantic meaning and specifies a text, which is stylistically different from a normal text, i.e., words or fragments of text that must be presented differently. These can be misspelled words or proper nouns in Chinese.

The <u> tag defines a span of text having an unarticulated but exactly rendered annotation. This means that the web developer and browser can choose how to show the annotation. Adding an annotation means adding a note or explanation. It must be non-textual. Browsers render a text surrounded by <u> tags as underlined, although it isn’t necessarily required.

The text in the <u> tag is being underlined (unless you style it otherwise).

This element should not be used just to underline the text because it is a deprecated HTML tag. For this purpose, use the CSS text-decoration property set to "underline".

In some cases, consider using other elements, such as:

  • <em> for stress emphasis,
  • <b> for drawing attention to a text,
  • <cite> for book titles,
  • <i> for technical terms,
  • <mark> for highlighting phrases or key words,
  • <strong> for specifying a text with strong importance.

If you want to add textual annotations, use the <ruby> tag.


The <u> element comes in pairs. The content is written between the opening (<u>) and closing (</u>) elements.

Example of the HTML <u> tag:

<!DOCTYPE html>
    <title>The title of the document</title>
    <p>Here we used <u>the &lt;u&gt; element</u>.</p>


u tag example

Example of the CSS text-decoration property:

<!DOCTYPE html>
    <title>The title of the document.</title>
      span {
        text-decoration: underline;
    <p>Here we used <span> CSS property text-decoration:underline</span>.</p>


The <u> tag supports the Global attributes and the Event Attributes.

How to style <u> tag?

Common properties to alter the visual weight/emphasis/size of text in <u> tag:

  • CSS font-style property sets the style of the font. normal | italic | oblique | initial | inherit.
  • CSS font-family property specifies a prioritized list of one or more font family names and/or generic family names for the selected element.
  • CSS font-size property sets the size of the font.
  • CSS font-weight property defines whether the font should be bold or thick.
  • CSS text-transform property controls text case and capitalization.
  • CSS text-decoration property specifies the decoration added to text, and is a shorthand property for text-decoration-line, text-decoration-color, text-decoration-style.

Coloring text in <u> tag:

  • CSS color property describes the color of the text content and text decorations.
  • CSS background-color property sets the background color of an element.

Text layout styles for <u> tag:

  • CSS text-indent property specifies the indentation of the first line in a text block.
  • CSS text-overflow property specifies how overflowed content that is not displayed should be signalled to the user.
  • CSS white-space property specifies how white-space inside an element is handled.
  • CSS word-break property specifies where the lines should be broken.

Other properties worth looking at for <u> tag:

Browser support

chrome edge firefox safari opera

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