emptyelement

An empty element, in the context of markup languages, refers to an element that contains no content and has no child elements. In XML and XHTML, an empty element is expressed with a self-closing tag such as <tag/>. In HTML, the analogue is the concept of void elements: elements that cannot contain content and do not have a separate end tag.

Void elements in HTML include img, br, hr, input, meta, link, area, base, col, embed, param, source, track, and wbr. These elements are defined by the HTML specification as inherently empty and should not enclose content or be written with a separate closing tag in standard practice. Other HTML elements can be written with opening and closing tags but may also be empty if they contain no text or child elements.

In XML and XHTML, the self-closing form is the standard way to denote emptiness; <tag/> is equivalent to <tag></tag> for elements with no content. In HTML, the self-closing syntax is generally ignored for non-void elements, and whether a closing tag is present may affect parsing results, but browsers typically treat non-void elements with no content as empty.

In the DOM, an empty element has no child nodes. Methods like textContent or innerHTML would yield an empty string (apart from possible whitespace). Empty elements can simplify markup and reduce data size, and they play a distinct role in parsing rules, serialization, and template processing across markup languages. See also: element, void element, self-closing tag, XML, HTML.