KaTeX is a faster alternative to MathJax. This plugin makes it easy to support in your markdown.

Need convincing?

• Check out the comparative benchmark: KaTeX vs MathJax
• Try it in your browser: md-it-katex demo

Usage

Install markdown-it

npm install markdown-it

Install the plugin

npm install md-it-katex

Use CJS

var md = require('markdown-it')(),
  mk = require('md-it-katex');

md.use(mk);

// double backslash is required for javascript strings, but not html input
var result = md.render('# Math Rulez! \n  $\\sqrt{3x-1}+(1+x)^2$');

Use ESM

import md from 'markdown-it',
import mk from 'md-it-katex';

md.use(mk);

// double backslash is required for javascript strings, but not html input
var result = md.render('# Math Rulez! \n  $\\sqrt{3x-1}+(1+x)^2$');

Include the KaTeX stylesheet in your html:

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.16.9/katex.min.css" />

If you're using the default markdown-it parser, I also recommend the github stylesheet:

<link
  rel="stylesheet"
  href="https://cdn.jsdelivr.net/github-markdown-css/2.2.1/github-markdown.css"
/>

KaTeX options can be supplied with the second argument to use.

md.use(mk, { throwOnError: false, errorColor: ' #cc0000' });

Examples

Inline

Surround your LaTeX with a single $ on each side for inline rendering.

$\sqrt{3x-1}+(1+x)^2$

Block

Use two ($$) for block rendering. This mode uses bigger symbols and centers the result.

$$\begin{array}{c}

\nabla \times \vec{\mathbf{B}} -\, \frac1c\, \frac{\partial\vec{\mathbf{E}}}{\partial t} &
= \frac{4\pi}{c}\vec{\mathbf{j}}    \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \\

\nabla \times \vec{\mathbf{E}}\, +\, \frac1c\, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \\

\nabla \cdot \vec{\mathbf{B}} & = 0

\end{array}$$

Syntax

Math parsing in markdown is designed to agree with the conventions set by pandoc:

Anything between two $ characters will be treated as TeX math. The opening $ must
have a non-space character immediately to its right, while the closing $ must
have a non-space character immediately to its left, and must not be followed
immediately by a digit. Thus, $20,000 and $30,000 won’t parse as math. If for some
reason you need to enclose text in literal $ characters, backslash-escape them and
they won’t be treated as math delimiters.

Math Syntax Support

KaTeX is based on TeX and LaTeX. Support for both is growing. Here's a list of currently supported functions:

Function Support in KaTeX