PostHTML is a tool for transforming HTML/XML with JavaScript plugins. It allows you to process HTML files using a variety of plugins to perform tasks such as minification, templating, and more.
HTML Transformation
This feature allows you to transform HTML elements. In this example, all <div> tags are transformed into <span> tags.
const posthtml = require('posthtml');
const html = '<div class="foo">Hello World</div>';
posthtml()
.use(tree => {
tree.match({ tag: 'div' }, node => {
node.tag = 'span';
return node;
});
})
.process(html)
.then(result => console.log(result.html));HTML Minification
This feature allows you to minify HTML content. The example demonstrates how to collapse whitespace in the HTML string.
const posthtml = require('posthtml');
const html = '<div class="foo"> Hello World </div>';
const posthtmlMinifier = require('posthtml-minifier');
posthtml([posthtmlMinifier({ collapseWhitespace: true })])
.process(html)
.then(result => console.log(result.html));Templating
This feature allows you to use templating within your HTML. The example shows how to replace a placeholder with a dynamic value.
const posthtml = require('posthtml');
const expressions = require('posthtml-expressions');
const html = '<div>{{ message }}</div>';
posthtml([expressions({ locals: { message: 'Hello World' } })])
.process(html)
.then(result => console.log(result.html));html-minifier is a highly configurable, well-tested, JavaScript-based HTML minifier. It focuses on minifying HTML content, similar to the minification feature in PostHTML, but does not offer the same level of extensibility with plugins.
Cheerio is a fast, flexible, and lean implementation of core jQuery designed specifically for the server. It allows you to manipulate HTML and XML documents with a jQuery-like syntax. While it offers powerful DOM manipulation capabilities, it does not provide the same plugin-based architecture as PostHTML.
jsdom is a JavaScript implementation of the WHATWG DOM and HTML standards, primarily intended for use with Node.js. It allows you to create and manipulate a DOM tree, similar to PostHTML, but is more focused on providing a complete DOM environment rather than a plugin-based transformation system.
PostHTML is a tool for transforming HTML/XML with JS plugins. PostHTML itself is very small. It includes only a HTML parser, a HTML node tree API and a node tree stringifier.
All HTML transformations are made by plugins. And these plugins are just small plain JS functions, which receive a HTML node tree, transform it, and return a modified tree.
For more detailed information about PostHTML in general take a look at the docs.
| Name | Status | Description |
|---|---|---|
| posthtml-parser |  | Parser HTML/XML to PostHTMLTree |
| posthtml-render |  | Render PostHTMLTree to HTML/XML |
npm init posthtml
npm i -D posthtml
Sync
import posthtml from 'posthtml'
const html = `
<component>
<title>Super Title</title>
<text>Awesome Text</text>
</component>
`
const result = posthtml()
.use(require('posthtml-custom-elements')())
.process(html, { sync: true })
.html
console.log(result)
<div class="component">
<div class="title">Super Title</div>
<div class="text">Awesome Text</div>
</div>
:warning: Async Plugins can't be used in sync mode and will throw an Error. It's recommended to use PostHTML asynchronously whenever possible.
Async
import posthtml from 'posthtml'
const html = `
<html>
<body>
<p class="wow">OMG</p>
</body>
</html>
`
posthtml(
[
require('posthtml-to-svg-tags')(),
require('posthtml-extend-attrs')({
attrsTree: {
'.wow' : {
id: 'wow_id',
fill: '#4A83B4',
'fill-rule': 'evenodd',
'font-family': 'Verdana'
}
}
})
])
.process(html/*, options */)
.then((result) => console.log(result.html))
<svg xmlns="http://www.w3.org/2000/svg">
<text
class="wow"
id="wow_id"
fill="#4A83B4"
fill-rule="evenodd" font-family="Verdana">
OMG
</text>
</svg>
Directives
import posthtml from 'posthtml'
const php = `
<component>
<title><?php echo $title; ?></title>
<text><?php echo $article; ?></text>
</component>
`
const result = posthtml()
.use(require('posthtml-custom-elements')())
.process(html, {
directives: [
{ name: '?php', start: '<', end: '>' }
]
})
.html
console.log(result)
<div class="component">
<div class="title"><?php echo $title; ?></div>
<div class="text"><?php echo $article; ?></div>
</div>
npm i posthtml-cli
"scripts": {
"posthtml": "posthtml -o output.html -i input.html -c config.json"
}
npm run posthtml
npm i -D gulp-posthtml
import tap from 'gulp-tap'
import posthtml from 'gulp-posthtml'
import { task, src, dest } from 'gulp'
task('html', () => {
let path
const plugins = [ require('posthtml-include')({ root: `${path}` }) ]
const options = {}
src('src/**/*.html')
.pipe(tap((file) => path = file.path))
.pipe(posthtml(plugins, options))
.pipe(dest('build/'))
})
Check project-stub for an example with Gulp
npm i -D grunt-posthtml
posthtml: {
options: {
use: [
require('posthtml-doctype')({ doctype: 'HTML 5' }),
require('posthtml-include')({ root: './', encoding: 'utf-8' })
]
},
build: {
files: [
{
dot: true,
cwd: 'html/',
src: ['*.html'],
dest: 'tmp/',
expand: true,
}
]
}
}
npm i -D html-loader posthtml-loader
webpack.config.js
const config = {
module: {
loaders: [
{
test: /\.html$/,
loader: 'html!posthtml'
}
]
},
posthtml: (ctx) => ({
parser: require('posthtml-pug'),
plugins: [
require('posthtml-bem')()
]
})
}
export default config
webpack.config.js
import { LoaderOptionsPlugin } from 'webpack'
const config = {
module: {
rules: [
{
test: /\.html$/,
use: [
{
loader: 'html-loader',
options: { minimize: true }
},
{
loader: 'posthtml-loader'
}
]
}
]
},
plugins: [
new LoaderOptionsPlugin({
options: {
posthtml(ctx) {
return {
parser: require('posthtml-pug'),
plugins: [
require('posthtml-bem')()
]
}
}
}
})
]
}
export default config
$ npm i rollup-plugin-posthtml -D
# or
$ npm i rollup-plugin-posthtml-template -D
import { join } from 'path';
import posthtml from 'rollup-plugin-posthtml-template';
// or
// import posthtml from 'rollup-plugin-posthtml';
import sugarml from 'posthtml-sugarml'; // npm i posthtml-sugarml -D
import include from 'posthtml-include'; // npm i posthtml-include -D
export default {
entry: join(__dirname, 'main.js'),
dest: join(__dirname, 'bundle.js'),
format: 'iife',
plugins: [
posthtml({
parser: sugarml(),
plugins: [include()],
template: true // only rollup-plugin-posthtml-template
})
]
};
import pug from 'posthtml-pug'
posthtml().process(html, { parser: pug(options) }).then((result) => result.html)
| Name | Status | Description |
|---|---|---|
| posthtml-pug |  | Pug Parser |
| sugarml |  | SugarML Parser |
In case you want to develop your own plugin, we recommend using posthtml-plugin-starter to get started.
| Name | Status | Description |
|---|---|---|
| posthtml-md |  | Easily use context-sensitive markdown within HTML |
| posthtml-toc |  | Table of contents |
| posthtml-lorem |  | Add lorem ipsum placeholder text to any document |
| posthtml-retext |  | Extensible system for analysing and manipulating natural language |
| prevent-widows |  | Prevent widows from appearing at the end of paragraphs |
| posthtml-richtypo |  | Process HTML node text with Richtypo |
| Name | Status | Description |
|---|---|---|
| posthtml-doctype |  | Set !DOCTYPE |
| posthtml-head-elements |  | Include head elements from JSON file |
| posthtml-include |  | Include HTML |
| posthtml-modules |  | Include and process HTML |
| posthtml-extend |  | Extend Layout (Pug-like) |
| posthtml-extend-attrs |  | Extend Attrs |
| posthtml-expressions |  | Template Expressions |
| posthtml-inline-assets |  | Inline external scripts, styles, and images |
| posthtml-static-react |  | Render custom elements as static React components |
| posthtml-custom-elements |  | Use custom elements |
| posthtml-web-component |  | Web Component server-side rendering, Component as a Service (CaaS) |
| posthtml-spaceless |  | Remove whitespace between HTML tags |
| posthtml-cache |  | Add a nanoid to links in your tags |
| posthtml-highlight |  | Syntax highlight code elements |
| posthtml-pseudo |  | Add pseudo selector class names to elements |
| posthtml-noopener |  | Add rel="noopener noreferrer" to links that open in new tab |
| posthtml-noscript |  | Insert noscript content when JavaScript is disabled |
| posthtml-hash |  | Hash static CSS/JS assets |
| posthtml-insert-at |  | Append/prepend HTML to a selector |
| posthtml-plugin-remove-duplicates |  | Remove duplicated tags |
| posthtml-plugin-link-preload |  | Add preload/prefetch tags (or return equivalent headers) |
| posthtml-prism |  | Code syntax highlighting with Prism |
| posthtml-url-parameters |  | Add parameters to URLs |
| posthtml-safe-class-names |  | Replace escaped characters in class names and CSS selectors |
| posthtml-fetch |  | Fetch and render remote content |
| posthtml-mso |  | Makes it easy to write Outlook conditionals in HTML emails |
| posthtml-postcss-merge-longhand |  | Merge longhand inline CSS into shorthand |
| posthtml-markdownit |  | Transform Markdown using markdown-it |
| posthtml-extra-attributes |  | Add new attributes to elements in your HTML |
| posthtml-sri |  | Adds subresource integrity (SRI) attributes. |
| Name | Status | Description |
|---|---|---|
| posthtml-bem |  | Support BEM naming in html structure |
| posthtml-postcss |  | Use PostCSS in HTML document |
| posthtml-px2rem |  | Change px to rem in Inline CSS |
| posthtml-css-modules |  | Use CSS modules in HTML |
| posthtml-postcss-modules |  | CSS Modules in html |
| posthtml-classes |  | Get a list of classes from HTML |
| posthtml-prefix-class |  | Prefix class names |
| posthtml-modular-css |  | Make CSS modular |
| posthtml-inline-css |  | CSS Inliner |
| posthtml-collect-styles |  | Collect styles from html and put it in the head |
| posthtml-collect-inline-styles |  | Collect inline styles and insert to head tag |
| posthtml-style-expantion |  | PostHTML plugin expand link rel="stylesheet". |
| posthtml-style-to-file |  | Save HTML style nodes and attributes to CSS file |
| posthtml-color-shorthand-hex-to-six-digit |  | Enforce all hex color codes to be 6-char long |
| posthtml-minify-classnames |  | Rewrites classnames and ids inside of html and css files to reduce file size. |
| Name | Status | Description |
|---|---|---|
| posthtml-img-autosize |  | Auto setting the width and height of <img> |
| posthtml-to-svg-tags |  | Convert html tags to svg equivalents |
| posthtml-webp |  | Add WebP support for images |
| posthtml-favicons |  | Generate Favicons and add related tags |
| posthtml-inline-svg |  | Inline svg icons in HTML |
| posthtml-inline-favicon |  | Inline favicons in HTML |
| Name | Status | Description |
|---|---|---|
| posthtml-aria-tabs |  | Write accessible tabs with minimal markup |
| posthtml-alt-always |  | Always add alt attribute for images that don't have it |
| posthtml-schemas |  | Add microdata to your HTML |
| Name | Status | Description |
|---|---|---|
| posthtml-shorten |  | Shorten URLs in HTML |
| posthtml-uglify |  | Shorten CSS in HTML |
| posthtml-minifier |  | Minify HTML |
| posthtml-remove-attributes |  | Remove attributes unconditionally or with content match |
| posthtml-remove-tags |  | Remove tags with content match |
| posthtml-remove-duplicates |  | Remove duplicate elements from your html |
| posthtml-transformer |  | Process HTML by directives in node attrs, such as inline scripts and styles, remove useless tags, concat scripts and styles etc. |
| htmlnano |  | HTML Minifier |
| posthtml-link-noreferrer |  | Add rel="noopener" and rel="noreferrer" to all links that contain the attribute target="_blank" |
| posthtml-lazyload | | Add native lazyload attribute |
| posthtml-postcss-treeshaker |  | Tree shake styles for classes and ids in style tag |
| posthtml-external-link |  | Add rel="external noopenner nofollow" and target="_blank" to all external links |
| Name | Status | Description |
|---|---|---|
| posthtml-load-plugins |  | Autoload Plugins |
| posthtml-load-options |  | Autoload Options (Parser && Render) |
| posthtml-load-config |  | Autoload Config (Plugins && Options) |
| posthtml-w3c |  | Validate HTML with W3C Validation |
| posthtml-hint |  | Lint HTML with HTML Hint |
| posthtml-tidy |  | Sanitize HTML with HTML Tidy |
| Name | Status | Description |
|---|---|---|
| koa-posthtml |  | Koa Middleware |
| hapi-posthtml |  | Hapi Plugin |
| express-posthtml |  | Express Middleware |
| electron-posthtml |  | Electron Plugin |
| metalsmith-posthtml |  | Metalsmith Plugin |
Ivan Demidov |
Ivan Voischev |
See PostHTML Guidelines and CONTRIBUTING.
Thank you to all our backers! 🙏 [Become a backer]
FAQs
HTML/XML processor
The npm package posthtml receives a total of 577,790 weekly downloads. As such, posthtml popularity was classified as popular.
We found that posthtml demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 2 open source maintainers collaborating on the project.
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