Empty element - MDN Web Docs Glossary: Definitions of Web-related terms 编辑

An empty element is an element from HTML, SVG, or MathML that cannot have any child nodes (i.e., nested elements or text nodes).

The HTML, SVG, and MathML specifications define very precisely what each element can contain. Many combinations have no semantic meaning, for example an <audio> element nested inside an <hr> element.

In HTML, using a closing tag on an empty element is usually invalid. For example, <input type="text"></input> is invalid HTML.

The empty elements in HTML are as follows:

• <area>
• <base>
• <br>
• <col>
• <embed>
• <hr>
• <img>
• <input>
• <keygen>(HTML 5.2 Draft removed)
• <link>
• <meta>
• <param>
• <source>
• <track>
• <wbr>