When writing in HTML, the <sub> tag is an inline element used to designate subscript text, which appears lower, and usually smaller, than the text around it. It is useful for tasks like writing mathematical or chemical formulas. The following sections contain information about this tag, including an example of it in use, as well as related attributes and browser compatibility.
Tip: For superscript text, use the <sup> tag.
<p>This chemical formula for ammonia is NH<sub>3</sub>.</p>