HTML <sub> Tag

The <sub> tag is used to define the subscript text that appears half a character below the line, and is rendered in a smaller font. Subscript text is often used for defining chemical formulas.

To define superscript text, use the <sup> tag.


The content of the tag is between the opening (<sub>) and the closing (</sub>) tags.


<!DOCTYPE html>
    <title>Title of the document</title>
    <p>Formula of water - H<sub>2</sub>O,  formula of alcohol - C<sub>2</sub>H<sub>5</sub>ОН</p>



The <sub> tag supports the Global attributes and the Event Attributes.

How to style <sub> tag

Common properties to alter the visual weight/emphasis/size of text in <sub> tag:?

  • CSS font-style property sets the style of the font. normal | italic | oblique | initial | inherit
  • CSS font-family property specifies a prioritized list of one or more font family names and/or generic family names for the selected element.
  • CSS font-size property sets the size of the font.
  • CSS font-weight property defines whether the font should be bold or thick. CSS text-transform Property controls text case and capitalization.
  • CSS text-decoration property specifies the decoration added to text, and is a shorthand property for text-decoration-line, text-decoration-color, text-decoration-style

Coloring text in <sub> tag:

  • CSS color property describes the color of the text content and text decorations
  • CSS background-color property sets the background color of an element.

Text layout styles for <sub> tag:

  • CSS text-indent property specifies the indentation of the first line in a text block.
  • CSS text-overflow property specifies how overflowed content that is not displayed should be signaled to the user.
  • CSS white-space property specifies how white-space inside an element is handled.
  • CSS word-break property specifies where the lines should be broken.

Other properties worth looking at for <sub> tag

Browser support

Do you find this helpful?

Related articles