# Hosting Your Own Copy of MathJax¶

We recommend using a CDN service if you can, but you can also install MathJax on your own server, or locally on your own hard disk. You may need to do this if you are creating a custom build of MathJax, for example, or if you wish to use MathJax off-line.

## Acquiring the MathJax Code¶

In order to host your own version of MathJax, you must first obtain a
copy of the MathJax code. That can be done in several ways, the
easiest being to use `npm`

(the node package manager), or `git`

to
get MathJax from its GitHub development repository.

### Getting MathJax via npm¶

To include MathJax in your project, use the command

```
npm install mathjax
```

This will install MathJax in `node_modules/mathjax`

subdirectory of
your current directory. It will include the pre-built components in
the `node_modules/mathjax/es5`

directory.

If you need access to the source code, as well. Then use

```
npm install mathjax-full
```

which installs MathJax in the `node_modules/mathjax-full`

subdirectory, the source files for the components in
`node_modules/mathjax-full/components/src`

, the typescript source
files for MathJax in `node_modules/mathjax-full/ts`

, and the
compiled javascript files from the typescript source in
`node_modules/mathjax-full/js`

.

### Getting MathJax via git¶

To obtain a copy of MathJax from the GitHub component repository, use the command

```
git clone https://github.com/mathjax/MathJax.git mathjax
```

This will install a copy of MathJax in the `mathjax/es5`

directory.

If you need access to the source code as well, then use

```
git clone https://github.com/mathjax/MathJax-src.git mathjax
```

which will install the source code for MathJax in the
`mathjax`

sub-directory of your current directory. You will need to
compile the typescript source files and build the component files by
hand, as they are not part of the repository itself. To do this, do
the following:

```
cd mathjax
npm install
npm run compile
npm run make-components
cd ..
```

This will compile the typescript source files from the `mathjax/ts`

directory into javascript files in the `mathjax/js`

directory, and
then will build the component files from `mathjax/components/src`

into the `mathjax/es5`

directory.

## Make the Files Available¶

Once you have acquired the MathJax files by one of the methods
described above, you need to make the proper files available on your
web server. Note that most of the files in the MathJax distribution
are not needed on the server. For example, the `mathjax/ts`

directory is typescript source code for MathJax, and this is compiled
into the javascript files found in the `mathjax/js`

directory. But
even these are not the files you want on your server. These
javascript files are further processed into the MathJax components
stored in the `mathjax/es5`

files using the data in the
`mathjax/components/src`

directory.

It is the contents of the `mathjax/es5`

directory that
you want to make available on your server, as these are the files that
are served from the CDNs that provide MathJax. You should move them
to a convenient location on your server. This might be a top-level
directory called `mathjax`

, for example.

## Linking to you Your Copy of MathJax¶

You can include MathJax in your web page by putting

```
<script src="path-to-MathJax/tex-chtml.js" id="MathJax-script" async></script>
```

in your document’s `<head>`

block. Here, `tex-chtml.js`

is the
combined component that you are loading, and this is just an example; you
will need to pick the one you want to use. See the section on
Configuring and Loading MathJax for more details.

The `path-to-MathJax`

should be replaced by the URL for the main
MathJax directory, so if you have put the `mathjax/es5`

directory at the top level of you server’s web site and named it
`mathjax`

, you could use

```
<script src="/mathjax/tex-chtml.js" id="MathJax-script" async></script>
```

to load MathJax in your page. For example, your page could look like

```
<html>
<head>
...
<script src="/mathjax/tex-chtml.js" id="MathJax-script" async></script>
</head>
<body>
...
</body>
</html>
```

## Firefox and Local Fonts¶

Firefox’s same-origin security policy affects its ability to load web-based fonts, as described above. This has implications not only to cross-domain loading of MathJax, but also to using MathJax locally from your hard disk. Firefox’s interpretation of the same-origin policy for local files used to be that the “same domain” for a page is the directory where that page exists, or any of its subdirectories. This allowed MathJax to be loaded from a subdirectory of the director where the web page was loaded.

This is no longer the case with Firefox starting with version 68 and
going forward (see their documentation).
Now there is no same origin for a `file://`

URL (the origin for a
page loaded from a `file://`

URL is unique).

This means there are limited options for using MathJax in Firefox with a local copy of MathJax. The easiest option is to use the SVG output renderer rather than the CommonHTML output, as that does not require fonts to be loaded, so avoids the same-origin issue. Alternatively, you could install the MathJax TeX fonts as system fonts so that Firefox doesn’t hav to try to load them as web fonts.

This is an unfortunate restriction for MathJax (though we understand their reasoning), but it is a limitation imposed by Firefox’s security model that MathJax can not circumvent. Currently, this is not a problem for other browsers, though there is no guarantee that it won’t be in the future.