index.md

---

title: <msub>
slug: Web/MathML/Element/msub
browser-compat: mathml.elements.msub

---

{{MathMLRef}}

The <msub> MathML element is used to attach a subscript to an expression.

It uses the following syntax: <msub> base subscript </msub>.

Attributes

This element's attributes include the global MathML attributes as well as the following deprecated attribute:

• subscriptshift {{deprecated_inline}} {{Non-standard_Inline}}

  • : A <length-percentage> indicating the minimum amount to shift the baseline of the subscript down.

Note: For the subscriptshift attribute, some browsers may also accept legacy MathML lengths.

Examples

<math display="block">
  <msub>
    <mi>X</mi>
    <mn>1</mn>
  </msub>
</math>

{{ EmbedLiveSample('msub_example', 700, 200, "", "") }}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{ MathMLElement("msup") }} (Superscript)

• {{ MathMLElement("msubsup") }} (Subscript-superscript pair)

• {{ MathMLElement("mmultiscripts") }} (Prescripts and tensor indices)