HTML < sub > and < sup > Tags

Example

Subscript and superscript text:

<p>This text contains _subscript text.</p>

<p>This text contains ^superscript text.</p>

Definition and Usage

The <sub> tag defines subscript text. Subscript text appears half a character below the baseline.

Subscript text can be used for chemical formulas, like H₂O.

The <sup> tag defines superscript text. Superscript text appears half a character above the baseline.

Superscript text can be used for footnotes, like WWW^[1].

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Browser Support

The <sub> and <sup> tags are supported in all major browsers.

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Differences Between HTML and XHTML

NONE

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Standard Attributes

DTD indicates in which HTML 4.01/XHTML 1.0 DTD the attribute is allowed. S=Strict, T=Transitional, and F=Frameset.

The <sub> and <sup> tags support the following standard attributes:

Attribute	Value	Description	DTD
class	classname	Specifies a classname for an element	STF
dir	rtl ltr	Specifies the text direction for the content in an element	STF
id	id	Specifies a unique id for an element	STF
lang	language_code	Specifies a language code for the content in an element	STF
style	style_definition	Specifies an inline style for an element	STF
title	text	Specifies extra information about an element	STF
xml:lang	language_code	Specifies a language code for the content in an element, in XHTML documents	STF

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Event Attributes

The <sub> and <sup> tags support the following event attributes:

Attribute	Value	Description	DTD
onclick	script	Script to be run on a mouse click	STF
ondblclick	script	Script to be run on a mouse double-click	STF
onmousedown	script	Script to be run when mouse button is pressed	STF
onmousemove	script	Script to be run when mouse pointer moves	STF
onmouseout	script	Script to be run when mouse pointer moves out of an element	STF
onmouseover	script	Script to be run when mouse pointer moves over an element	STF
onmouseup	script	Script to be run when mouse button is released	STF
onkeydown	script	Script to be run when a key is pressed	STF
onkeypress	script	Script to be run when a key is pressed and released	STF
onkeyup	script	Script to be run when a key is released	STF