Css-inline NPM

css-inline

css-inline is a high-performance library for inlining CSS into HTML 'style' attributes.

This library is designed for scenarios such as preparing HTML emails or embedding HTML into third-party web pages.

For instance, the library transforms HTML like this:

<html>
    <head>
        <style>h1 { color:blue; }</style>
    </head>
    <body>
        <h1>Big Text</h1>
    </body>
</html>

into:

<html>
    <head></head>
    <body>
        <h1 style="color:blue;">Big Text</h1>
    </body>
</html>

Uses reliable components from Mozilla's Servo project
Inlines CSS from style and link tags
Removes style and link tags
Resolves external stylesheets (including local files)
Works on Linux, Windows, and macOS
Supports HTML5 & CSS3

Install

Install with npm:

npm install --save css-inline

Usage

import { inline } from "css-inline";

var inlined = inline(
  `
  <html>
    <head>
      <style>h1 { color:red }</style>
    </head>
    <body>
      <h1>Test</h1>
    </body>
  </html>
  `,
)
// Do something with the inlined HTML, e.g. send an email

Configuration

inline_style_tags. Specifies whether to inline CSS from "style" tags. Default: true
keep_style_tags. Specifies whether to keep "style" tags after inlining. Default: false
keep_link_tags. Specifies whether to keep "link" tags after inlining. Default: false
base_url. The base URL used to resolve relative URLs. If you'd like to load stylesheets from your filesystem, use the file:// scheme. Default: null
load_remote_stylesheets. Specifies whether remote stylesheets should be loaded. Default: true
extra_css. Extra CSS to be inlined. Default: null
preallocate_node_capacity. Advanced. Preallocates capacity for HTML nodes during parsing. This can improve performance when you have an estimate of the number of nodes in your HTML document. Default: 32

You can also skip CSS inlining for an HTML tag by adding the data-css-inline="ignore" attribute to it:

<head>
    <style>h1 { color:blue; }</style>
</head>
<body>
    <!-- The tag below won't receive additional styles -->
    <h1 data-css-inline="ignore">Big Text</h1>
</body>
</html>

The data-css-inline="ignore" attribute also allows you to skip link and style tags:

<head>
    <!-- Styles below are ignored -->
    <style data-css-inline="ignore">h1 { color:blue; }</style>
</head>
<body>
    <h1>Big Text</h1>
</body>