HTML Tags

HTML Tag

The  tag in HTML is used to display subscript text, which appears smaller and slightly below the baseline of normal text.
It is commonly used in mathematical formulas, chemical formulas, and footnotes.
It is an inline element.

Syntax

html

<sub>Subscript text</sub>

Attributes

Attribute	Description
class	Assigns one or more class names for styling.
id	Assigns a unique identifier to the element.
style	Adds inline CSS styles to customize appearance.
title	Provides additional information as a tooltip.

Example

html

<!DOCTYPE html>
<html>
<head>
  <title>SUB Tag Example</title>
  <style>
    .chemical {
      color: #2c3e50;
      font-size: 0.9em;
    }
  </style>
</head>
<body>
  <h1>HTML <sub> Tag Example</h1>
  <p>
    Water chemical formula: H<sub class="chemical" id="water-sub" title="Subscript">2</sub>O
  </p>
  <p>
    Example: CO<sub>2</sub> is carbon dioxide.
  </p>
</body>
</html>

Output

Browser Output

html

Use our TryIt Editor to see the output.

Browser Support

Chrome	Edge	Firefox	Safari	Opera	IE9+
Yes	Yes	Yes	Yes	Yes	Yes

The  tag displays text slightly below the baseline, often in smaller font size, making it ideal for chemical formulas, footnotes, or mathematical notation.

Notes

 is an inline element and does not break the line.
CSS can be used to further style subscript text (color, font-size).
Often paired with  for superscripts in formulas and citations.
Avoid overusing for normal text; it is meant for specialized notation.

Conclusion

The  tag is used for subscript text, commonly in chemical, mathematical, or scientific contexts.
It visually shifts the text below the baseline, ensuring proper formatting for technical content.

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