rehype-katex

[![Build][build-badge]][build]
[![Coverage][coverage-badge]][coverage]
[![Downloads][downloads-badge]][downloads]
[![Size][size-badge]][size]
[![Sponsors][sponsors-badge]][collective]
[![Backers][backers-badge]][collective]
[![Chat][chat-badge]][chat]

[rehype][] plugin to render elements with a language-math class with
[KaTeX][].

* What is this?
* When should I use this?
* Install
* Use
* API
* [unified().use(rehypeKatex[, options])](#unifieduserehypekatex-options)
* Options
* Markdown
* HTML
* CSS
* Types
* Compatibility
* Security
* Related
* Contribute
* License

What is this?

This package is a [unified][] ([rehype][]) plugin to render math.
You can add classes to HTML elements, use fenced code in markdown, or combine
with [remark-math][remark-math] for a $C$ syntax extension.

When should I use this?

This project is useful as it renders math with KaTeX at compile time, which
means that there is no client side JavaScript needed.

A different plugin, [rehype-mathjax][rehype-mathjax], does the same but with
[MathJax][].

Install

This package is [ESM only][esm].
In Node.js (version 16+), install with [npm][]:

``sh npm install rehype-katex`

In Deno with [esm.sh][esmsh]:

`js import rehypeKatex from 'https://esm.sh/rehype-katex@7'`

In browsers with [esm.sh][esmsh]:

`html`

`Use`

Say our document input.html contains:

`html

Lift(L) can be determined by Lift Coefficient (C_L) like the following equation.



  L = \frac{1}{2} \rho v^2 S C_L

…and our module example.js contains:

`js import rehypeDocument from 'rehype-document' import rehypeKatex from 'rehype-katex' import rehypeParse from 'rehype-parse' import rehypeStringify from 'rehype-stringify' import {read, write} from 'to-vfile' import {unified} from 'unified'

const file = await unified() .use(rehypeParse, {fragment: true}) .use(rehypeDocument, { // Get the latest one from: . css: 'https://cdn.jsdelivr.net/npm/katex@0.16.8/dist/katex.min.css' }) .use(rehypeKatex) .use(rehypeStringify) .process(await read('input.html'))

file.basename = 'output.html' await write(file)`

…then running node example.js creates an output.html with:

`html input

Lift() can be determined by Lift Coefficient () like the following equation.

…open output.html in a browser to see the rendered math.

`API`

This package exports no identifiers. The default export is [rehypeKatex][api-rehype-katex].

`$3`

Render elements with a language-math (or math-display, math-inline) class with [KaTeX][].

###### Parameters

* options ([Options][api-options]) — configuration

###### Returns

Transform ([Transformer][unified-transformer]).

`$3`

Configuration (TypeScript type).

###### Type

`ts import {KatexOptions} from 'katex'

type Options = Omit`

See [Options on katex.org][katex-options] for more info.

`Markdown`

This plugin supports the syntax extension enabled by [remark-math][remark-math]. It also supports math generated by using fenced code:

``markdown`math C_L```

`HTML`

The content of any element with a language-math, math-inline, ormath-displayclass is transformed. The elements are replaced by what KaTeX renders. Either amath-display class or using

 will
result in “display” math: math that is a centered block on its own line.
CSS
The HTML produced by KaTeX requires CSS to render correctly.
You should use katex.css somewhere on the page where the math is shown to
style it properly.
At the time of writing, the last version is:
`html


`
Types
This package is fully typed with [TypeScript][].
It exports the additional type [Options][api-options].
Compatibility
Projects maintained by the unified collective are compatible with maintained
versions of Node.js.
When we cut a new major release, we drop support for unmaintained versions of
Node.
This means we try to keep the current release line, rehype-katex@^7,
compatible with Node.js 16.
This plugin works with unified version 6+ and rehype version 4+.
Security
Assuming you trust KaTeX, using rehype-katex is safe.
A vulnerability in it could open you to a
[cross-site scripting (XSS)][wiki-xss] attack.
Be wary of user input and use [rehype-sanitize][rehype-sanitize].
When you don’t trust user content but do trust KaTeX, run rehype-katex
after rehype-sanitize:
`js
import rehypeKatex from 'rehype-katex'
import rehypeSanitize, {defaultSchema} from 'rehype-sanitize'
import rehypeStringify from 'rehype-stringify'
import remarkMath from 'remark-math'
import remarkParse from 'remark-parse'
import remarkRehype from 'remark-rehype'
import {unified} from 'unified'
const file = await unified()
  .use(remarkParse)
  .use(remarkMath)
  .use(remarkRehype)
  .use(rehypeSanitize, {
    ...defaultSchema,
    attributes: {
      ...defaultSchema.attributes,
      // The language-* regex is allowed by default.
      code: [['className', /^language-./, 'math-inline', 'math-display']]
    }
  })
  .use(rehypeKatex)
  .use(rehypeStringify)
  .process('$C$')
console.log(String(file))
`
Related
* [rehype-mathjax][rehype-mathjax]
  — same but with MathJax
* rehype-highlight
  — highlight code blocks
* rehype-autolink-headings
  — add links to headings
* rehype-sanitize
  — sanitize HTML
* rehype-document
  — wrap a document around the tree
Contribute
See [contributing.md][contributing] in [remarkjs/.github][health] for ways
to get started.
See [support.md`][support] for ways to get help.
This project has a [code of conduct][coc].
By interacting with this repository, organization, or community you agree to
abide by its terms.
License
[MIT][license] © [Junyoung Choi][author]
[build-badge]: https://github.com/remarkjs/remark-math/workflows/main/badge.svg
[build]: https://github.com/remarkjs/remark-math/actions
[coverage-badge]: https://img.shields.io/codecov/c/github/remarkjs/remark-math.svg
[coverage]: https://codecov.io/github/remarkjs/remark-math
[downloads-badge]: https://img.shields.io/npm/dm/rehype-katex.svg
[downloads]: https://www.npmjs.com/package/rehype-katex
[size-badge]: https://img.shields.io/bundlejs/size/rehype-katex
[size]: https://bundlejs.com/?q=rehype-katex
[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg
[backers-badge]: https://opencollective.com/unified/backers/badge.svg
[collective]: https://opencollective.com/unified
[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg
[chat]: https://github.com/remarkjs/remark/discussions
[npm]: https://docs.npmjs.com/cli/install
[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c
[esmsh]: https://esm.sh
[health]: https://github.com/remarkjs/.github
[contributing]: https://github.com/remarkjs/.github/blob/main/contributing.md
[support]: https://github.com/remarkjs/.github/blob/main/support.md
[coc]: https://github.com/remarkjs/.github/blob/main/code-of-conduct.md
[license]: https://github.com/remarkjs/remark-math/blob/main/license
[author]: https://rokt33r.github.io
[katex]: https://github.com/Khan/KaTeX
[katex-options]: https://katex.org/docs/options.html
[rehype]: https://github.com/rehypejs/rehype
[rehype-sanitize]: https://github.com/rehypejs/rehype-sanitize
[unified]: https://github.com/unifiedjs/unified
[unified-transformer]: https://github.com/unifiedjs/unified#transformer
[typescript]: https://www.typescriptlang.org
[wiki-xss]: https://en.wikipedia.org/wiki/Cross-site_scripting
[mathjax]: https://www.mathjax.org
[remark-math]: ../remark-math/
[rehype-mathjax]: ../rehype-mathjax/
[api-options]: #options
[api-rehype-katex]: #unifieduserehypekatex-options

`rehype-katex`

[![Build][build-badge]][build] [![Coverage][coverage-badge]][coverage] [![Downloads][downloads-badge]][downloads] [![Size][size-badge]][size] [![Sponsors][sponsors-badge]][collective] [![Backers][backers-badge]][collective] [![Chat][chat-badge]][chat]

[rehype][] plugin to render elements with a language-math class with [KaTeX][].

`Contents`

* What is this? * When should I use this? * Install * Use * API * [unified().use(rehypeKatex[, options])](#unifieduserehypekatex-options) * Options * Markdown * HTML * CSS * Types * Compatibility * Security * Related * Contribute * License

`What is this?`

This package is a [unified][] ([rehype][]) plugin to render math. You can add classes to HTML elements, use fenced code in markdown, or combine with [remark-math][remark-math] for a $C$ syntax extension.

`When should I use this?`

This project is useful as it renders math with KaTeX at compile time, which means that there is no client side JavaScript needed.

A different plugin, [rehype-mathjax][rehype-mathjax], does the same but with [MathJax][].

`Install`

This package is [ESM only][esm]. In Node.js (version 16+), install with [npm][]:

``sh npm install rehype-katex `

In Deno with [esm.sh][esmsh]:

`js import rehypeKatex from 'https://esm.sh/rehype-katex@7' `

In browsers with [esm.sh][esmsh]:

`html `

`Use`

Say our document input.html contains:

`html

Lift(L) can be determined by Lift Coefficient (C_L) like the following equation.



  L = \frac{1}{2} \rho v^2 S C_L

`…and our module example.js contains:
`js
import rehypeDocument from 'rehype-document'
import rehypeKatex from 'rehype-katex'
import rehypeParse from 'rehype-parse'
import rehypeStringify from 'rehype-stringify'
import {read, write} from 'to-vfile'
import {unified} from 'unified'
const file = await unified()
  .use(rehypeParse, {fragment: true})
  .use(rehypeDocument, {
    // Get the latest one from: .
    css: 'https://cdn.jsdelivr.net/npm/katex@0.16.8/dist/katex.min.css'
  })
  .use(rehypeKatex)
  .use(rehypeStringify)
  .process(await read('input.html'))
file.basename = 'output.html'
await write(file)
`
…then running node example.js creates an output.html with:
`html




input





  Lift() can be determined by Lift Coefficient
  () like the following equation.




`…open output.html in a browser to see the rendered math.
API
This package exports no identifiers.
The default export is [rehypeKatex][api-rehype-katex].
$3
Render elements with a language-math (or math-display, math-inline)
class with [KaTeX][].
###### Parameters
* options ([Options][api-options])
  — configuration
###### Returns
Transform ([Transformer][unified-transformer]).
$3
Configuration (TypeScript type).
###### Type
`ts
import {KatexOptions} from 'katex'
type Options = Omit
`
See [Options on katex.org][katex-options] for more info.
Markdown
This plugin supports the syntax extension enabled by
[remark-math][remark-math].
It also supports math generated by using fenced code:
``markdown
`math
C_L
`
``
HTML
The content of any element with a language-math, math-inline, or
math-display class is transformed.
The elements are replaced by what KaTeX renders.
Either a math-display class or using 
 will
result in “display” math: math that is a centered block on its own line.
CSS
The HTML produced by KaTeX requires CSS to render correctly.
You should use katex.css somewhere on the page where the math is shown to
style it properly.
At the time of writing, the last version is:
`html


`
Types
This package is fully typed with [TypeScript][].
It exports the additional type [Options][api-options].
Compatibility
Projects maintained by the unified collective are compatible with maintained
versions of Node.js.
When we cut a new major release, we drop support for unmaintained versions of
Node.
This means we try to keep the current release line, rehype-katex@^7,
compatible with Node.js 16.
This plugin works with unified version 6+ and rehype version 4+.
Security
Assuming you trust KaTeX, using rehype-katex is safe.
A vulnerability in it could open you to a
[cross-site scripting (XSS)][wiki-xss] attack.
Be wary of user input and use [rehype-sanitize][rehype-sanitize].
When you don’t trust user content but do trust KaTeX, run rehype-katex
after rehype-sanitize:
`js
import rehypeKatex from 'rehype-katex'
import rehypeSanitize, {defaultSchema} from 'rehype-sanitize'
import rehypeStringify from 'rehype-stringify'
import remarkMath from 'remark-math'
import remarkParse from 'remark-parse'
import remarkRehype from 'remark-rehype'
import {unified} from 'unified'
const file = await unified()
  .use(remarkParse)
  .use(remarkMath)
  .use(remarkRehype)
  .use(rehypeSanitize, {
    ...defaultSchema,
    attributes: {
      ...defaultSchema.attributes,
      // The language-* regex is allowed by default.
      code: [['className', /^language-./, 'math-inline', 'math-display']]
    }
  })
  .use(rehypeKatex)
  .use(rehypeStringify)
  .process('$C$')
console.log(String(file))
`
Related
* [rehype-mathjax][rehype-mathjax]
  — same but with MathJax
* rehype-highlight
  — highlight code blocks
* rehype-autolink-headings
  — add links to headings
* rehype-sanitize
  — sanitize HTML
* rehype-document
  — wrap a document around the tree
Contribute
See [contributing.md][contributing] in [remarkjs/.github][health] for ways
to get started.
See [support.md`][support] for ways to get help.
This project has a [code of conduct][coc].
By interacting with this repository, organization, or community you agree to
abide by its terms.
License
[MIT][license] © [Junyoung Choi][author]
[build-badge]: https://github.com/remarkjs/remark-math/workflows/main/badge.svg
[build]: https://github.com/remarkjs/remark-math/actions
[coverage-badge]: https://img.shields.io/codecov/c/github/remarkjs/remark-math.svg
[coverage]: https://codecov.io/github/remarkjs/remark-math
[downloads-badge]: https://img.shields.io/npm/dm/rehype-katex.svg
[downloads]: https://www.npmjs.com/package/rehype-katex
[size-badge]: https://img.shields.io/bundlejs/size/rehype-katex
[size]: https://bundlejs.com/?q=rehype-katex
[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg
[backers-badge]: https://opencollective.com/unified/backers/badge.svg
[collective]: https://opencollective.com/unified
[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg
[chat]: https://github.com/remarkjs/remark/discussions
[npm]: https://docs.npmjs.com/cli/install
[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c
[esmsh]: https://esm.sh
[health]: https://github.com/remarkjs/.github
[contributing]: https://github.com/remarkjs/.github/blob/main/contributing.md
[support]: https://github.com/remarkjs/.github/blob/main/support.md
[coc]: https://github.com/remarkjs/.github/blob/main/code-of-conduct.md
[license]: https://github.com/remarkjs/remark-math/blob/main/license
[author]: https://rokt33r.github.io
[katex]: https://github.com/Khan/KaTeX
[katex-options]: https://katex.org/docs/options.html
[rehype]: https://github.com/rehypejs/rehype
[rehype-sanitize]: https://github.com/rehypejs/rehype-sanitize
[unified]: https://github.com/unifiedjs/unified
[unified-transformer]: https://github.com/unifiedjs/unified#transformer
[typescript]: https://www.typescriptlang.org
[wiki-xss]: https://en.wikipedia.org/wiki/Cross-site_scripting
[mathjax]: https://www.mathjax.org
[remark-math]: ../remark-math/
[rehype-mathjax]: ../rehype-mathjax/
[api-options]: #options
[api-rehype-katex]: #unifieduserehypekatex-options

rehype-katex

rehype-katex

Contents

What is this?

When should I use this?

Install

`Use`

`API`

`$3`

`$3`

`Markdown`

`HTML`

CSS

`Types`

`Compatibility`

`Security`

`Related`

`Contribute`

License

`rehype-katex`

`rehype-katex`

`Contents`

`What is this?`

`When should I use this?`

`Install`

`Use`

`API`

`$3`

`$3`

`Markdown`

`HTML`

CSS

`Types`

`Compatibility`

`Security`

`Related`

`Contribute`

License