Summary
The HTML Subscript Element (<sub>) defines a span of text that should be displayed, for typographic reasons, lower, and often smaller, than the main span of text.
Usage note:
- This element should be used for typographical reasons only, i.e. changing the position of the text changing its meaning like in mathematical (like t2, though the use of a MathML formula should be considered) or chemical formulas (like H2O).
- This element must not be used for styling purpose like the styling of the product name Latex. In that case CSS style should be used: the
vertical-alignproperty with thesubvalue will achieve the same effect.
Usage context
| Content categories | Flow content and phrasing content |
| Permitted content | Phrasing content |
| Tag omission | None as both the start and end tag are mandatory |
| Permitted parent elements | Any element that can contain phrasing content |
| Normative document | HTML5, section 4.6.14 (HTML4.01, section 9.2.3) |
Attributes
This element only includes the global attributes.
DOM interface
This element implements the HTMLElement interface.
Implementation note: up to Gecko 1.9.2 inclusive, Firefox implements the HTMLSpanElement interface for this element.
Examples
<p>The chemical formula of water is H<sub>2</sub>O</p>
Result
The chemical formula of water is H2O
See also
- The
<sup>HTML element that produces superscript. Note that you cannot use them both at the same time and you need to use MathML to produce both a superscript and a subscript next to the chemical symbol of an element, representing its atomic number and its nuclear number. - The
<msub>,<msup>, and<msubsup>MathML elements.