Project: rehypejs/rehype-minify

Package: rehype-concat-javascript@3.0.0

  1. Dependents: 0
  2. rehype plugin to concatenate JS <script> elements together
  1. unified 175
  2. plugin 132
  3. html 123
  4. rehype 89
  5. rehype-plugin 62
  6. minify 31
  7. mangle 31
  8. javascript 24
  9. script 10
  10. combine 3
  11. concat 2


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rehype plugin to concatenate <script>s together.


What is this?

This package is a plugin that can improve performance by merging multiple JS <script> elements together. This plugin can be dangerous if JavaScript is invalid or values are expected to be undefined in one script but not in another.

When should I use this?

You can use this plugin when you are certain that your JavaScript is and you want to improve the size of HTML.


This package is ESM only. In Node.js (version 12.20+, 14.14+, or 16.0+), install with npm:

npm install rehype-concat-javascript

In Deno with esm.sh:

import rehypeConcatJavaScript from 'https://esm.sh/rehype-concat-javascript@3'

In browsers with esm.sh:

<script type="module">
  import rehypeConcatJavaScript from 'https://esm.sh/rehype-concat-javascript@3?bundle'


On the API:

import {read} from 'to-vfile'
import {unified} from 'unified'
import rehypeParse from 'rehype-parse'
import rehypeStringify from 'rehype-stringify'
import rehypeConcatJavaScript from 'rehype-concat-javascript'


async function main() {
  const file = await unified()
    .process(await read('index.html'))


On the CLI:

rehype input.html --use rehype-concat-javascript --output output.html

On the CLI in a config file (here a package.json):

 "rehype": {
   "plugins": [
+    "rehype-concat-javascript",


This package exports no identifiers. The default export is rehypeConcatJavaScript.


Concatenate <script> elements together. There are no options.


<script>function foo() {}</script>
<script>function bar() {}</script>
<script>function foo() {};function bar() {}</script>


HTML is handled according to WHATWG HTML (the living standard), which is also followed by browsers such as Chrome and Firefox.

Syntax tree

The syntax tree format used is hast.


This package is fully typed with TypeScript.


Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 12.20+, 14.14+, and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.


As rehype works on HTML, and improper use of HTML can open you up to a cross-site scripting (XSS) attack, use of rehype can also be unsafe. Use rehype-sanitize to make the tree safe.


See contributing.md in rehypejs/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.


MIT © Titus Wormer