@mdit/plugin-katex

Plugins to render math expressions with KaTeX.

Note

This plugin is based on @mdit/plugin-tex.

Usage

import { katex } from "@mdit/plugin-katex";
import MarkdownIt from "markdown-it";

const mdIt = new MarkdownIt().use(katex);

mdIt.render("$E=mc^2$");

We also have a package called @mdit/plugin-katex-slim which katex is an optional peer.

Syntax

The syntax depends on the delimiters option:

Default ("dollars"): Use $tex expression$ inline, and $$tex expression$$ for block.
LaTeX style ("brackets"): Use $tex expression$ inline, and \[tex expression\] for block.
Both ("all"): Both dollar and bracket syntaxes are supported.

Style

You should import katex/dist/katex.min.css from katex package or CDN yourself.

Escaping

You can use \ to escape $ \( and \[:
```
Euler’s identity \$e^{i\pi}+1=0$
```
will be
Euler’s identity $e^{i\pi}+1=0$

Options

This plugin extends KaTeX options. Available options include:

delimiters"brackets" | "dollars" | "all"

Default"dollars"

Math delimiter syntax to enable.

"brackets": Use $...$ for inline math and \[...\] for display math (LaTeX style).
"dollars": Use $...$ for inline math and $$...$$ for display math (common Markdown style).
"all": Enable both bracket and dollar syntaxes.

mathFenceboolean

Defaultfalse

Whether parsed fence block with math language to display mode math.

allowInlineWithSpaceboolean

Defaultfalse

Whether to allow inline math with spaces on ends. NOT recommended to set this to true, because it will likely break the default usage of $. Note that a space-padded literal $ inside the content (e.g. $\text{a $ b}$) is then treated as a closing $, closing the expression early.

loggerKatexLogger

type KatexLogger<MarkdownItEnv = unknown> = (
  errorCode:
    | "unknownSymbol"
    | "unicodeTextInMathMode"
    | "mathVsTextUnits"
    | "commentAtEnd"
    | "htmlExtension"
    | "newLineInDisplayMode",
  errorMsg: string,
  token: Token | undefined,
  env: MarkdownItEnv,
) => "error" | "warn" | "ignore" | boolean | undefined;

Error logger function.

transformer(content: string, displayMode: boolean) => string

Transformer function on output content.

Demo

Euler’s identity $e^{i π} + 1 = 0$ is a beautiful formula in $R^{2}$ .

\frac{\partial^{r}}{\partial ω^{r}} (\frac{y^{ω}}{ω}) = (\frac{y^{ω}}{ω}) {(\log y)^{r} + \sum_{i = 1}^{r} \frac{(- 1)^{i} r \dots (r - i + 1) (\log y)^{r - i}}{ω^{i}}}

Demo

Euler’s identity $e^{i\pi}+1=0$ is a beautiful formula in $\mathbb{R}^2$.

$$
\frac {\partial^r} {\partial \omega^r} \left(\frac {y^{\omega}} {\omega}\right)
= \left(\frac {y^{\omega}} {\omega}\right) \left\{(\log y)^r + \sum_{i=1}^r \frac {(-1)^i r \cdots (r-i+1) (\log y)^{r-i}} {\omega^i} \right\}
$$

mhchem extension

If you want to load the mhchem extension, you should import @mdit/plugin-katex/mhchem:

import { katex } from "@mdit/plugin-katex";
import "@mdit/plugin-katex/mhchem";

Support List

Cookbook

$T E X$ Cookbook

See the comparison report for the full upstream comparison.