mathsize

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The mathsize global attribute sets the font-size of a MathML element.

Note: Use CSS for styling MathML whenever possible. The mathsize attribute should only be included for applications that are not CSS-aware and will be overridden by the CSS font-size property, if set.

Example

html,
body {
  height: 100%;
}

body {
  display: grid;
  place-items: center;
}

html

<math display="block">
  <msup mathsize="16px">
    <mi>a</mi>
    <mn>2</mn>
  </msup>
  <mo>+</mo>
  <msup mathsize="24px">
    <mi>b</mi>
    <mn>2</mn>
  </msup>
  <mo>=</mo>
  <msup mathsize="32px">
    <mi>c</mi>
    <mn>2</mn>
  </msup>
</math>

Syntax

html

<!-- <length> values -->
<math mathsize="12px">
<math mathsize="0.8em">

<!-- <percentage> values -->
<math mathsize="80%">

Values

<length>: A positive <length> value. For most font-relative units (such as em and ex), the font size is relative to the parent element's font size.
<percentage>: A positive <percentage> value, relative to the parent element's font size.

Note: Some browsers may also accept legacy MathML lengths.

Specifications

Specification
MathML Core # dfn-mathsize

In MathML 3 and earlier versions, keywords small, normal, and big as well as the MathML3-specific syntax for lengths was supported. Since MathML Core, the syntax matches CSS <length-percentage> values.
This attribute was designed for MathML applications that are not CSS-aware. Since MathML Core, the use of equivalent CSS is recommended instead.

Browser compatibility

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`mathsize` Deprecated	Chrome – Full support Chrome 109 (Release date: 2023-01-10) footnote Full support	Edge – Full support Edge 109 (Release date: 2023-01-12) footnote Full support	Firefox – Partial support Firefox 1 – 69 (Release date: 2004-11-09) footnote Partial support footnote Attribute only accepted on a few elements, as specified in MathML 3. Firefox – Full support Firefox 70 (Release date: 2019-10-22) footnote footnote See https://hg.mozilla.org/mozilla-central/rev/3b30c8db537c	Opera – Full support Opera 95 (Release date: 2023-02-01) footnote Full support	Safari – Full support Safari 5 (Release date: 2010-06-07) footnote footnote See https://trac.webkit.org/changeset/63079	Chrome Android – Full support Chrome Android 109 (Release date: 2023-01-10) footnote Full support	Firefox for Android – Partial support Firefox for Android 4 – 68 (Release date: 2011-03-29) footnote Partial support footnote Attribute only accepted on a few elements, as specified in MathML 3. Firefox for Android – Full support Firefox for Android 79 (Release date: 2020-07-28) footnote footnote See https://hg.mozilla.org/mozilla-central/rev/3b30c8db537c	Opera Android – Full support Opera Android 74 (Release date: 2023-03-13) footnote Full support	Safari on iOS – Full support Safari on iOS 4.2 (Release date: 2010-11-22) footnote footnote See https://trac.webkit.org/changeset/63079	Samsung Internet – Full support Samsung Internet 21 (Release date: 2023-05-19) footnote Full support	WebView Android – Full support WebView Android 109 (Release date: 2023-01-10) footnote Full support	WebView on iOS – Full support WebView on iOS 4.2 (Release date: 2010-11-22) footnote footnote See https://trac.webkit.org/changeset/63079
Named spaces (e.g. `thinmathspace` to mean 3/18em) Deprecated Non-standard	Chrome – No support Chrome footnote No support	Edge – No support Edge footnote No support	Firefox – Full support Firefox 1 (Release date: 2004-11-09) footnote Full support	Opera – No support Opera footnote No support	Safari – Full support Safari 10 (Release date: 2016-09-20) footnote Full support	Chrome Android – No support Chrome Android footnote No support	Firefox for Android – Full support Firefox for Android 4 (Release date: 2011-03-29) footnote Full support	Opera Android – No support Opera Android footnote No support	Safari on iOS – Full support Safari on iOS 10 (Release date: 2016-09-13) footnote Full support	Samsung Internet – No support Samsung Internet footnote No support	WebView Android – No support WebView Android footnote No support	WebView on iOS – Full support WebView on iOS 10 (Release date: 2016-09-13) footnote Full support
Nonzero unitless values (e.g. 5 to mean 500%) Deprecated Non-standard	Chrome – No support Chrome footnote No support	Edge – No support Edge footnote No support	Firefox – No support Firefox 1 – 69 (Release date: 2004-11-09) footnote Removed in 70 and later	Opera – No support Opera footnote No support	Safari – Full support Safari 10 (Release date: 2016-09-20) footnote Full support	Chrome Android – No support Chrome Android footnote No support	Firefox for Android – No support Firefox for Android 4 – 68 (Release date: 2011-03-29) footnote Removed in 79 and later	Opera Android – No support Opera Android footnote No support	Safari on iOS – Full support Safari on iOS 10 (Release date: 2016-09-13) footnote Full support	Samsung Internet – No support Samsung Internet footnote No support	WebView Android – No support WebView Android footnote No support	WebView on iOS – Full support WebView on iOS 10 (Release date: 2016-09-13) footnote Full support
`small`, `normal`, `big` values Deprecated Non-standard	Chrome – No support Chrome footnote No support	Edge – No support Edge footnote No support	Firefox – No support Firefox 1 – 82 (Release date: 2004-11-09) footnote Removed in 83 and later	Opera – No support Opera footnote No support	Safari – Full support Safari 5 (Release date: 2010-06-07) footnote Full support	Chrome Android – No support Chrome Android footnote No support	Firefox for Android – No support Firefox for Android 4 – 82 (Release date: 2011-03-29) footnote Removed in 83 and later	Opera Android – No support Opera Android footnote No support	Safari on iOS – Full support Safari on iOS 4.2 (Release date: 2010-11-22) footnote Full support	Samsung Internet – No support Samsung Internet footnote No support	WebView Android – No support WebView Android footnote No support	WebView on iOS – Full support WebView on iOS 4.2 (Release date: 2010-11-22) footnote Full support

Tip: you can click/tap on a cell for more information.

Full support: Full support
Partial support: Partial support
No support: No support
: Non-standard. Check cross-browser support before using.
: Deprecated. Not for use in new websites.
: See implementation notes.
: Has more compatibility info.