MathJax Output Formats

MathJax Output Components

Currently, MathJax can render math in three ways:

  • Using HTML-with-CSS to lay out the mathematics,
  • Using SVG to lay out the mathematics, or
  • Using a browser’s native MathML support.

These are implemented by the CommonHTML, HTML-CSS, and PreviewHTML output processors, the SVG output processor, and the NativeMML output processor respectively. In addition, the PlainSource output is a convenience and accessibility output, rendering the source as plain text.

If you are using one of the combined configuration files, then this will select one of these output processors for you. If the config file ends in _CHTML, then it is the CommonHTML output processor, if it ends in _HTML, then it is the HTML-CSS output processor, and if it ends in _SVG then the SVG output processor will be used. If it ends in _HTMLorMML, HTML-CSS output will be used except on Internet Explorer 9 or below with the MathPlayer plugin; cf. HTMLorMML extension (deprecated).

If you are performing your own in-line or file-based configuration, you select which one you want to use by including either "output/CommonHTML", output/HTML-CSS, "output/SVG", or "output/NativeMML" in the jax array of your MathJax configuration. For example



The CommonHTML output processor produces high-quality output in all modern browsers, with results that are consistent across browsers and operating systems. This is MathJax’s primary output mode since MathJax v2.6. Its major advantage is its quality, consistency, and speed as well as support for server-side generation. Its browser supports starts with IE9 and equivalent browsers and it degrades gracefully on older browsers. The CommonHTML output uses web-based fonts so that users don’t have to have math fonts installed on their computers, but will use locally installed ones if they are available. It currently only supports MathJax’s default TeX fonts.

The HTML-CSS output processor produces high-quality output in all browsers, with results that are consistent across browsers and operating systems. This was MathJax’s primary output mode prior to MathJax v2.6. Its major advantage is its quality and consistency on legacy browsers starting with IE6. The HTML-CSS output uses web-based fonts so that users don’t have to have math fonts installed on their computers but can use locally installed fonts instead.

The SVG output processor uses Scalable Vector Graphics to render the mathematics on the page. SVG is supported in all the major browsers and most mobile devices; note, however, that Internet Explorer prior to IE9 does not support SVG, and IE9 only does in “IE9 standards mode”, not its emulation modes for earlier versions. The SVG output mode is high quality and somewhat faster than HTML-CSS, and it does not suffer from some of the font-related issues that HTML-CSS does, so prints well in all browsers. Since it uses SVG data instead of font files, it is not affected by user based web-font blocking. One disadvantage of this mode is that its variable-width tables become fixed size once they are typeset, and don’t rescale if the window size changes (for example). Since equation numbers are handled through variable-width tables, that means equation numbers may not stay at the edge of the window if it is resized. Also, because its mathematical characters are produced by paths, not characters in a font, they can’t be copy and pasted, as the output of the HTML-based processors can.


The advantage of the NativeMML output processor is its speed, since native MathML support is usually faster than converting to HTML-with-CSS and SVG. The disadvantage is that you are dependent on the browser’s MathML implementation for your rendering, and these vary in quality of output and completeness of implementation. MathJax relies on features that are not available in some renderers (for example, Firefox’s MathML support does not implement the features needed for labeled equations). While MathJax’s NativeMML output processor works around various limitations of Firefox/Gecko and Safari/WebKit, the results using the NativeMML output processor may have spacing, font, or other rendering problems that are outside of MathJax’s control.

The PreviewHTML output processor produces fast but low-quality output in all modern browsers. It is designed to serve as a fast preview mode as its layout quality is nowhere near the quality of the CommonHTML, HTML-CSS, and SVG output processors. Its major advantage is its speed. Its browser supports starts with IE8. It uses locally installed Times-like fonts and does not load any webfonts.

The PlainSource output processor injects the plain text source of the equations instead of a typeset version; if the input is MathML, the output processor will prefer TeX and AsciiMath notation (in that order) if it is available in <annotation> elements. This output is a convenience output for users who prefer raw source, e.g., users who need to copy and paste larger document fragments and users of assistive technologies.

Automatic Line Breaking

The CommonHTML, HTML-CSS, and SVG output processors implement (most of) the MathML3 automatic line-breaking specification. (The NativeMML output processor relies on the browser’s native MathML support to handle line breaking when it is used.) Since line-breaking takes extra processing and so can slow down the mathematical output, it is off by default, but you can enable it by adding, e.g.,

  CommonHTML: { linebreaks: { automatic: true } },
         SVG: { linebreaks: { automatic: true } }

to your page just before the <script> tag that loads MathJax.js itself.


Line breaking only applies to displayed equations, not in-line equations (unless the in-line equation is itself longer than a line), and the line-breaks are only computed once when the equation is initially typeset, and do not change if the user changes the window size, or if the container changes size for some other reason.

You can control what width is used to determine where the line breaks shoud occur using the container parameter of the linebreaks block. By default it is the width of the containing element, but you can make it a fixed width, or make it a percentage of the container. See the CommonHTML configuration, HTML-CSS configuration, or SVG configuration pages for more details.

Note that breaks occur only at operations and relations or at explicit space, but not, for example, in the middle of two consecutive identifiers, and long identifiers or numbers are not broken, nor are the contents of <mtext> elements (which come from the \text{} macro in TeX input).

The line-breaking algorithm uses the nesting depth, the type of operator, the size of spaces, and other factors to decide on the breakpoints, but it does not know the meaning of the mathematics, and may not choose the optimal breakpoints. We continue to work on the algorithm as we gain information from its actual use in the field. If you are using MathML as your input format, you can use the linebreak="newline", linebreak="goodbreak", linebreak="badbreak", and linebreak="nobreak" attributes on <mo> elements to help MathJax pick the best breakpoints for your mathematics; nested <mrow> elements will reduce the risk of breaking its children apart. For TeX input, you can use MathJax’s non-standard mmltoken macro (e.g., \mmlToken{mo}[linebreak="goodbreak"]{}) and braces {...} respectively to achieve analoguous effects.

Automatic Selection of the Output Processor

Since not all browsers support MathML natively, it would be unwise to choose the NativeMML output processor unless you are sure of your audience’s browser capabilities. Similarly, you might want more control over which platforms use which renderer.

While MathJax used to provide an extension to handle switching between HTML-CSS and NativeMML output, this limited extension was deprecated in MathJax v2.6.

Instead, you can use the regular MathJax configuration methods to define which output to use where.

In general, you can do the following:

MathJax.Hub.Register.StartupHook("End Jax",function () {
  var BROWSER = MathJax.Hub.Browser;
  var jax = "HTML-CSS";
  if (BROWSER.isMSIE && BROWSER.hasMathPlayer) jax = "NativeMML";
  return MathJax.Hub.setRenderer(jax);

This does essentially what the MMLorHTML configuration did in its default settings. You can, of course, substitute whatever output you want in place of HTML-CSS or NativeMML, and you can add other if-then statements for other browsers. E.g.,

MathJax.Hub.Register.StartupHook("End Jax",function () {
  var BROWSER = MathJax.Hub.Browser;
  var jax = "HTML-CSS";
  if (BROWSER.isFirefox) jax = "SVG";
  if (BROWSER.isSafari && BROWSER.versionAtLeast("5.0")) jax = "NativeMML";
  return MathJax.Hub.setRenderer(jax);

This illustrates using BROWSER.versionAtLeast() to make some decisions. You can, of course, be as complicated as you like about making the choices. For example, you could detect if a user is blocking web-fonts and switch to SVG output (which does not rely on fonts but SVG data files).

If you want something that is more backward compatible with MMLorHTML (i.e., if you have pages that configure MMLorHTML one way and other apges that configure it another way), here is a version that uses the old MMLorHTML’s “prefer” object, and only sets MathML mode if they browser can handle that.

MathJax.Hub.Register.StartupHook("End Jax",function () {
  var BROWSER = MathJax.Hub.Browser;

  var canUseMML = (BROWSER.isFirefox && BROWSER.versionAtLeast("1.5")) ||
                  (BROWSER.isMSIE    && BROWSER.hasMathPlayer) ||
                  (BROWSER.isSafari  && BROWSER.versionAtLeast("5.0")) ||
                  (BROWSER.isOpera   && BROWSER.versionAtLeast("9.52") &&

  var CONFIG = MathJax.Hub.CombineConfig("MMLorHTML",{
    prefer: {
      MSIE:"MML", Firefox:"HTML", Opera:"HTML", Chrome:"HTML", Safari:"HTML",

  var jax = CONFIG.prefer[BROWSER] || CONFIG.prefer.other;
  if (jax === "HTML") jax = "HTML-CSS"; else if (jax === "MML")  jax = "NativeMML";
  if (jax === "NativeMML" && !canUseMML) jax = CONFIG.prefer.other;
  return MathJax.Hub.setRenderer(jax);

The deprecated MMLorHTML extension also included version checking to see if MathJax is supported in the browser, but there shouldn’t be a need for that any longer as those older browsers (IE5 and below) just aren’t used any more.

HTMLorMML extension (deprecated)


This extension has been deprecated in MathJax v2.6. See the section above for alternatives.

With the decline of MathPlayer, the general lack of development of native MathML implementations, and the increase in output options in MathJax, we have decided to deprecate the HTMLorMML extension in MathJax v2.6.

Originally, a number of combined configuration files would select NativeMML output when the browser supports it well enough, and HTML-CSS output otherwise. These are the configuration files that end in _HTMLorMML.

These configurations added the "MMLorHTML.js" extension to your configuration’s config array, and they would not include an output processor in your jax array; MathJax will fill that in for you based on the abilities of your user’s browser.

By default, this extension would choose HTML-CSS in all browsers except for one case: Internet Explorer 9 and below when the MathPlayer plugin is present.

In recent versions of MathJax, this extension would choose HTML-CSS in all Internet Explorer versions when the MathPlayer plugin is present. However, due to lack of support for MathPlayer in Internet Explorer 10 and above, we have restricted this further. In the v1.x releases, MathJax selected NativeMML output for Firefox as well, but we have found that there are too many rendering issues with Firefox’s native MathML implementation, and so MathJax v2.0+ selected HTML-CSS output for Firefox by default as well.

Users can still use the Mathjax contextual menu to select the NativeMML renderer if they wish to.


See the config/default.js file or the Configuring MMLorHTML section for further details.

HTML-CSS Extensions

The HTML-CSS output jax uses elements with width set to 100% when it typesets displayed equations. If there are floating elements on the left or right, this can mean that displayed mathematics isn’t properly centered, and can cause equation numbers to overlap the floating content. To avoid this, you can specify the handle-floats extension in the extensions array of your HTML-CSS configuration block.

  extensions: ["handle-floats.js"]

This will use CSS that puts the displayed equations into elements that work like tabel cells, and won’t overlap the floaring content. Because this is somewhat of a misuse of CSS, it is not used by default, but it has proved successful in most situations, so you may consider using it in pages that include material that floats to the left or right of text containing displayed mathematics, especially when equation numbers or tags are used.

See the HTML-CSS configuration options for other options of the HTML-CSS output jax.

Viewport meta tag

The meta viewport tag provides the browser with instructions regarding viewports and zooming. This way, web developers can control how a webpage is displayed on a mobile device.

Incorrect or missing viewport information can confuse MathJax’s layout process, leading to very small font sizes. We recommend that you use standard values such as the following:


Internet Explorer Emulation modes

Internet Explorer provides so-called emulation modes for backward compatibility to its legacy versions. These emulation modes have been deprecated since Internet Explorer 11, cf. Microsoft documentation.

MathJax is fastest when in the standards mode of each IE version, so it is best to force the highest mode possible. That can be accomplished by adding


at the top of the <head> section of your HTML documents.


This line must come at the beginning of the <head>, before any stylesheets, scripts, or other content are loaded.

In early versions, we recommended forcing IE8 and IE9 into IE7-emulation mode in order to get better performance. That is no longer necessary.