The MathML <mi> element indicates that the content should be rendered as an identifier such as function names, variables or symbolic constants. You can also have arbitrary text in it to mark up terms.


class, id, style
Provided for use with stylesheets.
The text direction. Possible values are either ltr (left to right) or rtl (right to left).
A Boolean value specifying whether more vertical space is used for displayed equations or, if set to false, a more compact layout is used to display formulas. The main effect is that larger versions of operators are displayed, when displaystyle is set to true. See also largeop and movablelimits on <mo>.
Used to set a hyperlink to a specified URI.
The background color. You can use #rgb, #rrggbb and HTML color names.
The text color. You can use #rgb, #rrggbb and HTML color names.
The size of the content. See length for possible values.
Deprecated values are: small, normal and big. These will be removed in the future.
This logical class of the identifier, which varies in typography. That is, although the names suggest the typographic style for the class, semantically, items with the same class are treated "the same" within an expression, which might or might not involve displaying them with the named typography. The following values are allowed:
  • normal (Default value for more than one character) ; Example
  • bold ; Example
  • italic (Default value for a single character) ; Example
  • bold-italic ; Example
  • double-struck ; Example
  • bold-fraktur ; Example
  • script ; Example
  • bold-script ; Example
  • fraktur ; Example
  • sans-serif ; Example
  • bold-sans-serif ; Example
  • sans-serif-italic ; Example
  • sans-serif-bold-italic ; Example
  • monospace ; Example
  • initial ; مثال
  • tailed ; مثال
  • looped ; مثال
  • stretched ; مثال



  <mi> y </mi>

  <mi> sin </mi>

  <mi mathvariant="monospace"> x </mi>

  <mi mathvariant="bold"> &pi; </mi>



Specification Status Comment
MathML Core
The definition of 'mi' in that specification.
Draft Draft specification
MathML 3.0
The definition of 'mi' in that specification.
Recommendation Current specification
MathML 2.0
The definition of 'mi' in that specification.
Recommendation Initial specification

Browser compatibility

BCD tables only load in the browser

Gecko-specific notes

  • Some mathvariant values are only implemented starting with Gecko 28.0 (Firefox 28.0 / Thunderbird 28.0 / SeaMonkey 2.25) and require appropriate math fonts.