hast utility to transform to something else (react, vue, etc) through a hyperscript DSL

Usage no npm install needed!

<script type="module">
  import hastToHyperscript from 'https://cdn.skypack.dev/hast-to-hyperscript';



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hast utility to transform a tree to something else through a hyperscript interface.


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


npm install hast-to-hyperscript


import {toH} from 'hast-to-hyperscript'
import h from 'hyperscript'

const tree = {
  type: 'element',
  tagName: 'p',
  properties: {id: 'alpha', className: ['bravo']},
  children: [
    {type: 'text', value: 'charlie '},
      type: 'element',
      tagName: 'strong',
      properties: {style: 'color: red;'},
      children: [{type: 'text', value: 'delta'}]
    {type: 'text', value: ' echo.'}

// Transform (`hyperscript` needs `outerHTML` to serialize):
const doc = toH(h, tree).outerHTML



<p class="bravo" id="alpha">charlie <strong>delta</strong> echo.</p>


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

toH(h, tree[, options|prefix])

Transform a hast tree to something else through a hyperscript interface.

  • h (Function) — Hyperscript function
  • tree (Node) — Tree to transform
  • prefix — Treated as {prefix: prefix}
  • options.prefix (string or boolean, optional) — Prefix to use as a prefix for keys passed in attrs to h(), this behavior is turned off by passing false, turned on by passing a string. By default, h- is used as a prefix if the given h is detected as being virtual-dom/h or React.createElement
  • options.space (enum, 'svg' or 'html', default: 'html') — Whether node is in the 'html' or 'svg' space. If an svg element is found when inside the HTML space, toH automatically switches to the SVG space when entering the element, and switches back when exiting

* — Anything returned by invoking h().

function h(name, attrs, children)

Create an element from the given values.


h is called with the node that is currently compiled as the context object (this).

  • name (string) — Tag-name of element to create
  • attrs (Object.<string>) — Attributes to set
  • children (Array.<* | string>) — List of children (results of previously invoking h())

* — Anything.


Most hyperscript implementations only support elements and texts. hast supports doctype, comment, and root as well.

  • If anything other than an element or root node is given, toH throws
  • If a root is given with no children, an empty div element is returned
  • If a root is given with one element child, that element is transformed
  • Otherwise, the children are wrapped in a div element

If unknown nodes (a node with a type not defined by hast) are found as descendants of the given tree, they are ignored: only text and element are transformed.


Although there are lots of libraries mentioning support for a hyperscript-like interface, there are significant differences between them. For example, hyperscript doesn’t support classes in attrs and virtual-dom/h needs an attributes object inside attrs most of the time. toH works around these differences for:


Use of hast-to-hyperscript can open you up to a cross-site scripting (XSS) attack if the hast tree is unsafe. Use hast-util-sanitize to make the hast tree safe.



See contributing.md in syntax-tree/.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