markdown-it-katex

Add Math to your Markdown

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: markdown-it-katex demo

Usage

Install the plugin

npm i @elastic-code/markdow-it-katex

or

pnpm add @elastic-code/markdow-it-katex

Use it in your javascript

import md from "markdown-it";
//import library
import mk from "@elastic-code/markdow-it-katex";
//import styles

md.use(mk);

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

Add styles

<link
  rel="stylesheet"
  href="https://cdn.jsdelivr.net/npm/[email protected]/dist/katex.min.css"
  integrity="sha384-veTAhWILPOotXm+kbR5uY7dRamYLJf58I7P+hJhjeuc7hsMAkJHTsPahAl0hBST0"
  crossorigin="anonymous" />

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