# MathJax Frequently Asked Questions

- Which license is MathJax distributed under?

- Will MathJax make my page load slower even if there’s no math?

- Mathematics is not rendering properly in IE. How do I fix that?

- What should IE’s X-UA-Compatible meta tag be set to?

- Some of my mathematics is too large or too small. How do I get it right?

- My mathematics is private. Is it safe to use MathJax?

- Does MathJax support Presentation and/or Content MathML?

- How do I create mathematical expressions for display with MathJax?

- I ran into a problem with MathJax. How do I report it?

- Why doesn’t the TeX macro \something work?

- Does MathJax support user-defined TeX macros?

## Which license is MathJax distributed under?

MathJax is distributed under the Apache License, Version 2.0.

## Will MathJax make my page load slower even if there’s no math?

It depends on how you have configured and loaded MathJax. The combined component files like tex-chtml.js contain a full copy of MathJax and all the components needed for it to process the given input and output format, including all the font data (but not the actual fonts themselves). So these files can be quite large, and can take some time to download. On the other hand, it is a single file (unlike in version 2, where multiple files needed to be loaded), so there should not be the delays associated with establishing multiple connections to a server. If you use the async attribute on the script that loads MathJax, that allows the browser to put off loading MathJax until the rest of the page is ready, so that can help speed up your initial page loading as well.

## Mathematics is not rendering properly in IE. How do I fix that?

Currently, MathJax version 3 only supports IE11, so if you are using an earlier version, you will need to update your copy, or use a different browser.

If you are using IE11, then please open the MathJax homepage at www.mathjax.org in IE to see if that loads correctly. If the MathJax website does not display mathematics properly, there may be an issue with your security settings in Internet Explorer. Please check the following settings:

- “Active Scripting” under the Scripting section should be enabled, as it allows JavaScript to run.

- “Run ActiveX controls and Plugins” should be enabled (or prompted) in the “ActiveX Controls and Plugins” section.

- “Script ActiveX controls marked safe for scripting” needs to be enabled (or prompted) in the same “ActiveX Controls and Plugins” section. Note that it requires a restart of IE if you change this setting.

- “Font Download” has to be enabled (or prompted) in the “Downloads” section. This is required for MathJax to use web-based fonts for optimal viewing experience.

You may need to select Custom Level security to make these changes. If you have verified that the above settings are correct, tried clearing your cache and restarting IE. If you are still experiencing problems with displaying mathematics on `www.mathjax.org`, we would appreciate it if you reported the problem to the MathJax issue tracker so we can look into it. See the section on issue tracking for details.

If the MathJax site does render properly, this indicates that there may be something wrong with the webpage you were trying to view initially. If you manage that website, then make sure that it is using the latest version of MathJax. If you don’t manage the website yourself, you may have to report the issue to the maintainers of the site in order to have it resolved.

## What should IE’s X-UA-Compatible meta tag be set to?

We strongly suggest to follow Microsoft’s suggestion to use `IE=edge`. That is, in the document `<head>` include

    <meta http-equiv="X-UA-Compatible" content="IE=edge">

before any other tags in the `<head>`. This will force all IE versions to use their latest engine which is the optimal setting for MathJax. For more information, see the Microsoft documentation on compatibility modes.

## Some of my mathematics is too large or too small. How do I get it right?

MathJax renders mathematics dynamically so that formulas and symbols are nicely integrated into the surrounding text — with matching font size, margins, and baseline. In other words: it should look right. If your mathematics is too large or too small in comparison to its surroundings, you may be using the incorrect typesetting style. Following LaTeX conventions, MathJax supports two typesetting styles: in-line and “display” equations (one set off from the paragraph as a separate line). For in-line equations, MathJax tries hard to maintain the inter-line spacing. This means things like fractions and roots are vertically compressed, and smaller fonts are used. Display equations are shown as a separate paragraph and can be rendered with more space and slightly larger fonts. The standard delimiters for in-line equations in TeX notation are `\(...\)`, while those for display equations are `$$...$$` or `\[...\]`, but both types of delimiters can be customized. For how to configure MathJax to scale all mathematics relative to the surrounding text, check our documentation for Output Processor Options.

## My mathematics is private. Is it safe to use MathJax?

Yes. MathJax is JavaScript code that is runs within the user’s browser, so your site’s actual content never leaves the browser while MathJax is rendering. If you are using MathJax from a CDN, it interacts with a web server to get font data and MathJax code, but this is all put together in the browser of the reader. If you have concerns about cross-site scripting, you can access the CDN service using the secure `https` protocol to prevent tampering with the code between the CDN and a browser; or, if you prefer, you can install MathJax on your own web server, or for off-line use. MathJax does not reference scripts from other websites. The MathJax code is, of course, open source which means that you can review it and inspect its integrity.

## Does MathJax support Presentation and/or Content MathML?

MathML comes in two types: Presentation MathML, which describes what an equation looks like, and Content MathML, which describes what an equation means. By default, MathJax works with Presentation MathML and offers an extension for Content MathML, see the documentation on MathML support, which has not yet been converted to version 3.

You can also convert your Content MathML expressions to Presentation MathML using `xslt`, see for example David Carlisle’s web-xslt collection. A more detailed explanation of the difference between Content and Presentation MathML can be found in the module “Presentation MathML Versus Content MathML” at `cnx.org`.

## How do I create mathematical expressions for display with MathJax?

MathJax is a method to display mathematics. It is not an authoring environment, and so you will need another program to create mathematical expressions. The most common languages for mathematics on the computer are (La)TeX and MathML, and there are many authoring tools for these languages.

LaTeX code is essentially plain text, and so you do not need a special program to write it (although complete LaTeX authoring environments do exist). If you are not familiar with LaTeX, you will need some determination to learn and master the language due to its specialized nature and rich vocabulary of symbols. There are various good tutorials on the net, but there is no one-size-fits-all best one. A good starting point is the TeX User Group, or have a look at the LaTeX Wiki book.

MathML is an XML-based web format for mathematical expressions. MathML3, the latest version, has been an official W3C recommendation since October 2010. MathML is widely supported by Computer Algebra Systems and can be created with a choice of authoring tools, including Microsoft Office with the MathType equation editor. A list of software the supports MathML may be found in The W3C MathML software list.

## I ran into a problem with MathJax. How do I report it?

See the section on Reporting Issues for the steps to take when you think you have found a bug in MathJax.

## Why doesn’t the TeX macro `\something` work?

It really depends on what `\something` is. We have a full list of the Supported TeX/LaTeX commands. If the command you want to use is not in this list, you may be able to define a TeX macro for it yourself, or if you want to get really advanced, you can define custom JavaScript that implements it (see the Custom Extensions section for details).

Keep in mind that MathJax is meant for typesetting math on the web. It only replicates the math functionality of LaTeX and not the text formatting capabilities. Any text formatting on the web should be done in HTML and CSS, not TeX. If you would like to convert full TeX documents into HTML to publish online, you should use a TeX to HTML converter like LaTeXML, Tralics, or tex4ht, but you should realize that TeX conversion tools are unlikely produce results as good as controlling the HTML and CSS source yourself.

## Does MathJax support user-defined TeX macros?

Yes, you can define TeX macros in MathJax the same way you do in LaTeX with `\newcommand`, or `\def`. An example is `\newcommand{\water}{{\rm H_{2}O}}`, which will output the chemical formula for water when you use the `\water` command. The `\renewcommand` command works as well. You can also store macros in the MathJax configuration. For more information, see the documentation.