---
title: Syntax Highlighter Module
---

The Syntax Module enhances the Code Block format by automatically detecting and applying syntax highlighting. The excellent [highlight.js](https://highlightjs.org/) library is used as a dependency to parse and tokenize code blocks.

In general, you may [configure](https://highlightjs.readthedocs.io/en/latest/api.html#configure-options) highlight.js as needed. However, Quill expects and requires the `useBR` option to be `false` if you are using highlight.js < v11.

Quill supports highlight.js v9.12.0 and later.

### Usage

<Sandpack
  defaultShowPreview
  files={{
  "/index.html":  `
<!-- Include your favorite highlight.js stylesheet -->
<link href="{{site.highlightjs}}/styles/atom-one-dark.min.css" rel="stylesheet">

<!-- Include the highlight.js library -->
<script src="{{site.highlightjs}}/highlight.min.js"></script>

<link href="{{site.cdn}}/quill.snow.css" rel="stylesheet" />
<script src="{{site.cdn}}/quill.js"></script>

<div id="editor"></div>

<script>
const quill = new Quill('#editor', {
  modules: {
    syntax: true,              // Include syntax module
    toolbar: [['code-block']]  // Include button in toolbar
  },
  theme: 'snow'
});

const Delta = Quill.import('delta');
quill.setContents(
  new Delta()
    .insert('const language = "JavaScript";')
    .insert('\\n', { 'code-block': 'javascript' })
    .insert('console.log("I love " + language + "!");')
    .insert('\\n', { 'code-block': 'javascript' })
);
</script>
`}}
/>

If you install highlight.js as an npm package and don't want to expose it to `window`, you need to pass it to syntax module as an option:

```js
import Quill from 'quill';
import hljs from 'highlight.js';

const quill = new Quill('#editor', {
  modules: {
    syntax: { hljs },
  },
});
```