Customizing a mathfield

The appearance and behavior of the mathfield is highly customizable. Here are a few common examples.


The mathfield can be styled using the style attribute on the <math-field> tag, for example to change the base font size or add a border.

Change line 2-6 of the HTML in the playground below with color: #dde; background: #256291;.

<math-field style=" font-size: 32px; margin: 3em; padding: 8px; border-radius: 8px; border: 1px solid rgba(0, 0, 0, .3); box-shadow: 0 0 8px rgba(0, 0, 0, .2); "> x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} </math-field>

The content of the mathfield is displayed using a family of high-quality fonts based on the original Computer Modern font from TeX. The mathfield will not display correctly using another font. By default, the directory containing the fonts is located next to the file containing the mathlive library. If your bundler or asset management system require a different configuration you can specify where the fonts can be located using the fontsDirectory option or the fonts-directory attribute.

<math-field fonts-directory="//"> x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} </math-field>

Note that changing the fonts directory for one mathfield will change the fonts used by all the mathfields in the page.

Learn more about configuring the MathLive library to your environment, including using custom asset pipelines and bundlers in the Getting Started Guide.

CSS Variables

Some CSS variables can be used to modify the appearance of the mathfield:

  • --hue: (0…360) default is 212 (light blue). The default colors below are derived from this variable
  • --highlight: color of the selected fragment of the expression, when the mathfield is active
  • --highlight-inactive: selection color when the mathfield is not focused
  • --caret: color of the caret (insertion point)
  • --primary: accent color for some UI elements, such as the virtual keyboard toggle
  • --smart-fence-opacity: opacity of a smart gence (default is 50%)
  • --smart-fence-color: color of a smart fence (default is current color)
  • --text-font-family: the font stack used in text mode
<math-field style=" --hue: 53 !important; --caret: red !important; "> x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} </math-field>

Display Options

The appearance of a formula, in an editable mathfield or as a static representation, can be controlled with some of the following options:


To change the foreground (“ink”) and background (“paper”) colors of a formula programmatically, use the applyStyle() function.

To modify the foreground color you can also use the \textcolor{}{} command. To change the background, use the \colorbox{}{} command.

The first argument of these commands is a color specified as:

  • a RGB color using the standard CSS format (#d7170b)
  • a CSS color name (goldenrod)
  • one of the 68 colors from dvips color name (cadetblue)
  • one of the 10 Mathematica color from ColorData[97, "ColorList"] (m0 to m9)
  • a color defined using the syntax from the xcolor package, for example: blue!20!black!30!green

The following color names are recommended. They can be applied using the color keys in the virtual keyboard:

These colors have been carefully selected for a balanced representation of the range of hues on the color circle, with similar lightness and intensity. They will map to different color values than the dvips colors of the same name.

To have proper legibility based on usage, these color names will map to different values when used as a foreground color and a background color. To use a specific color value, use a RGB color instead.

To customize how the color names are interpreted provide a colorMap or backgroundColorMap function.


To change the base font size, set the font-size CSS property to the desired value on the mathfield or static element.

Within a formula, the size can be specified from a font scale with 10 values, where 1 em is the base font size.

fontSize command
1 0.5 em \tiny
2 0.7 em \tiny
3 0.8 em \footnotesize
4 0.9 em \small
5 1.0 em \normalsize or \normal
6 1.2 em \large
7 1.44 em \Large
8 1.728 em \LARGE
9 2.074 em \huge
10 2.488 em \Huge

In TeX, the sizing commands behave inconsistently when applied to math. Other implementations of TeX may also interpret the sizing commands differently.

Editing Options

Some configuration options can be specified when creating a mathfield as the argument of new MathfieldElement() or as an attribute to the &lt;math-field&gt; element. as we’ve see above with the fontsDirectory option.

The configuration options can also be changed programmatically using the setOptions() method.

Several of these configuration options affect the behavior while editing a formula:

  • defaultMode: if inline-math the math field is using inline math mode by default. If set to math, it will use the display math mode. If set to text it will use the text mode.
  • ignoreSpaceabrInMathMode: if false, insert a space when the spacebar is pressed, even in math mode (spaces are usually ignored in math mode)
  • removeExtraneousParentheses: automatically remove extra parentheses around a numerator or denominator
  • scriptDepth: maximum levels of subscript or superscript. Set it to 0 to prevent the input of superscript and subscripts
  • smartFence: automatically convert parentheses to \left...\right markup.
  • smartMode: switch to text mode when text input is detected, for example when typing “if x > 0”
  • smartSuperscript: automatically move out of a superscript when a digit is typed

In the code playground below, try some of these options. For example, change line 3 to scriptDepth: 0, then try to type “x^2” in the mathfield.

<math-field smart-mode > x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} </math-field>

See EditingOptions for more details about these and other available options.


The user interface of the mathfield is provided in english, arabic, german, greek, spanish, farsi, french, italian, japanese, polish and russian.

The language to use is detected automatically, but it can be overridden by using the locale option or the locale attribute.

Note: we await for the <math-field> definition to be loaded before invoking the getOptions() method, otherwise it would not be found.

await window.customElements.whenDefined('math-field'); const mf = document.getElementById('formula'); const locale = mf.getOptions('locale'); console.log("Locale:", locale); console.log(mf.getOptions().strings[locale]);
<math-field id='formula' virtual-keyboard-mode="manual" locale="fr"> x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} </math-field>


Executing commands
Send editing commands to a mathfield