Third-party Extensions

MathJax can load extensions (and configurations) from arbitrary locations. This allows authors and developers to easily integrate custom code.

Custom extension path configuration

Usually, third-party extensions have to be specified with their full paths (and matching loadComplete calls); this limits portability. To simplify this process, the MathJax configuration can include (possibly multiple) third-party locations for easier reference.

To specify the URL, set MathJax.Ajax.config.path["Extra"] in your configuration file, for example,

<script type="text/x-mathjax-config">
  MathJax.Ajax.config.path["Extra"] = "";

or equivalently,

<script type="text/javascript">
  window.MathJax = {
    AuthorInit: function () {
          MathJax.Ajax.config.path["Extra"] = "";

Configuring this path will allow you to load extensions using the [Extra] prefix. To continue the example, the following configuration would then load

  extensions: ["[Extra]/spiffy.js"]

Note that the extension’s loadComplete call needs to match this path, i.e., spiffy.js should end with


MathJax Third-Party extension repository

We host a third-party extension repository on the MathJax CDN. This repository allows developers to make their custom extensions easily available to all MathJax users.

The code of the repository is hosted on Github at and is mirrored to the CDN at

Beginning with MathJax v2.7, the third party repository URL is stored in the [Contrib] path variable. This makes it easy to load extension in that repository, e.g.,

  extensions: ["[Contrib]/spiffy/spiffy.js"]

For a list of available extensions available, please check the GitHub repo.


You can disable the [Contrib] path by loading MathJax with noContrib in the query string, e.g., MathJax.js?config=...&noContrib. This is particularly necessary when using your own copy of MathJax with a combined configuration file bit without access to