<u>: The Unarticulated Annotation (Underline) element

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

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The <u> HTML element represents a span of inline text which should be rendered in a way that indicates that it has a non-textual annotation. This is rendered by default as a single solid underline, but may be altered using CSS.

Warning: This element used to be called the "Underline" element in older versions of HTML, and is still sometimes misused in this way. To underline text, you should instead apply a style that includes the CSS text-decoration property set to underline.

Try it

<p>
  You could use this element to highlight <u>speling</u> mistakes, so the writer
  can <u>corect</u> them.
</p>

p {
  margin: 0;
}

u {
  text-decoration: #f00 wavy underline;
}

See the Usage notes section for further details on when it's appropriate to use <u> and when it isn't.

Attributes

This element only includes the global attributes.

Usage notes

Along with other pure styling elements, the original HTML Underline (<u>) element was deprecated in HTML 4; however, <u> was restored in HTML 5 with a new, semantic, meaning: to mark text as having some form of non-textual annotation applied.

Note: Avoid using the <u> element with its default styling (of underlined text) in such a way as to be confused with a hyperlink, which is also underlined by default.

Use cases

Valid use cases for the <u> element include annotating spelling errors, applying a proper name mark to denote proper names in Chinese text, and other forms of annotation.

You should not use <u> to underline text for presentation purposes, or to denote titles of books.

Other elements to consider using

In most cases, you should use an element other than <u>, such as:

  • <em> to denote stress emphasis
  • <b> to draw attention to text
  • <mark> to mark key words or phrases
  • <strong> to indicate that text has strong importance
  • <cite> to mark the titles of books or other publications
  • <i> to denote technical terms, transliterations, thoughts, or names of vessels in Western texts

To provide textual annotations (as opposed to the non-textual annotations created with <u>), use the <ruby> element.

To apply an underlined appearance without any semantic meaning, use the text-decoration property's value underline.

Examples

Indicating a spelling error

This example uses the <u> element and some CSS to display a paragraph which includes a misspelled error, with the error indicated in the red wavy underline style which is fairly commonly used for this purpose.

HTML

html
<p>This paragraph includes a <u class="spelling">wrnogly</u> spelled word.</p>

In the HTML, we see the use of <u> with a class, spelling, which is used to indicate the misspelling of the word "wrongly".

CSS

css
u.spelling {
  text-decoration: red wavy underline;
}

This CSS indicates that when the <u> element is styled with the class spelling, it should have a red wavy underline underneath its text. This is a common styling for spelling errors. Another common style can be presented using red dashed underline.

Result

The result should be familiar to anyone who has used any of the more popular word processors available today.

Avoiding <u>

Most of the time, you actually don't want to use <u>. Here are some examples that show what you should do instead in several cases.

Non-semantic underlines

To underline text without implying any semantic meaning, use a <span> element with the text-decoration property set to "underline", as shown below.

HTML
html
<span class="underline">Today's Special</span>
<br />
Chicken Noodle Soup With Carrots
CSS
css
.underline {
  text-decoration: underline;
}
Result

Presenting a book title

Book titles should be presented using the <cite> element instead of <u> or even <i>.

Using the cite element
html
<p>The class read <cite>Moby-Dick</cite> in the first term.</p>
Styling the cite element

The default styling for the <cite> element renders the text in italics. You can override that using CSS:

html
<p>The class read <cite>Moby-Dick</cite> in the first term.</p>
css
cite {
  font-style: normal;
  text-decoration: underline;
}

Technical summary

Content categories Flow content, phrasing content, palpable content.
Permitted content Phrasing content.
Tag omission None, both the starting and ending tag are mandatory.
Permitted parents Any element that accepts phrasing content.
Implicit ARIA role generic
Permitted ARIA roles Any
DOM interface HTMLElement

Specifications

Specification
HTML
# the-u-element

Browser compatibility

See also