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hast utility to transform Parse5’s AST to a hast tree.


This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required.


npm install hast-util-from-parse5


Say we have the following file, example.html:

<!doctype html><title>Hello!</title><h1 id="world">World!<!--after-->

And our script, example.js, looks as follows:

import parse5 from 'parse5'
import {readSync} from 'to-vfile'
import {inspect} from 'unist-util-inspect'
import {fromParse5} from 'hast-util-from-parse5'

const file = readSync('example.html')
const p5ast = parse5.parse(String(file), {sourceCodeLocationInfo: true})
const hast = fromParse5(p5ast, file)


Now, running node example yields:

root[2] (1:1-2:1, 0-70)
│ data: {"quirksMode":false}
├─0 doctype<html> (1:1-1:16, 0-15)
│     public: null
│     system: null
└─1 element<html>[2]
    │ properties: {}
    ├─0 element<head>[1]
    │   │ properties: {}
    │   └─0 element<title>[1] (1:16-1:37, 15-36)
    │       │ properties: {}
    │       └─0 text "Hello!" (1:23-1:29, 22-28)
    └─1 element<body>[1]
        │ properties: {}
        └─0 element<h1>[3] (1:37-2:1, 36-70)
            │ properties: {"id":"world"}
            ├─0 text "World!" (1:52-1:58, 51-57)
            ├─1 comment "after" (1:58-1:70, 57-69)
            └─2 text "\n" (1:70-2:1, 69-70)


This package exports the following identifiers: fromParse5. There is no default export.

fromParse5(ast[, file|options])

Transform Parse5’s AST to a hast tree.


If options is a VFile, it’s treated as {file: options}.

Whether the root of the tree is in the 'html' or 'svg' space (enum, 'svg' or 'html', default: 'html').

If an element in with the SVG namespace is found in ast, fromParse5 automatically switches to the SVG space when entering the element, and switches back when leaving.


VFile, used to add positional information to nodes. If given, the file should have the original HTML source as its contents.


Whether to add extra positional information about starting tags, closing tags, and attributes to elements (boolean, default: false). Note: not used without file.

For the following HTML:

<img src="" alt="foo" title="bar">

The verbose info would looks as follows:

  type: 'element',
  tagName: 'img',
  properties: {src: '', alt: 'foo', title: 'bar'},
  children: [],
  data: {
    position: {
      opening: {
        start: {line: 1, column: 1, offset: 0},
        end: {line: 1, column: 61, offset: 60}
      closing: null,
      properties: {
        src: {
          start: {line: 1, column: 6, offset: 5},
          end: {line: 1, column: 38, offset: 37}
        alt: {
          start: {line: 1, column: 39, offset: 38},
          end: {line: 1, column: 48, offset: 47}
        title: {
          start: {line: 1, column: 49, offset: 48},
          end: {line: 1, column: 60, offset: 59}
  position: {
    start: {line: 1, column: 1, offset: 0},
    end: {line: 1, column: 61, offset: 60}


Use of hast-util-from-parse5 can open you up to a cross-site scripting (XSS) attack if Parse5’s AST is unsafe.



See in syntax-tree/.github for ways to get started. See 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