css-inline

main branch1 version

main branchlatestFeb 6, 2026

github.com/osbre/css-inline

Crystal bindings to high-performance library for inlining CSS into HTML 'style' attributes.

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0 dependents

License: MIT

Installation

# Add this to your shard.yml
dependencies:
  css-inline:
    github: osbre/css-inline
    branch: main

main is a branch, not a release, so this tracks it rather than pinning a version.

Then run:

shards install

shard.yml

Crystal: >= 1.19.1
License: MIT
Author: Ostap Brehin

Dependencies

This version declares no dependencies.

README

css-inline

Crystal bindings for css-inline — a high-performance library for inlining CSS into HTML. Perfect for preparing HTML emails or embedding HTML into third-party web pages.

Prerequisites

Rust toolchain (the C library is compiled from source during installation)

Installation

Add the dependency to your shard.yml:

dependencies:
  css-inline:
    github: osbre/css-inline

Run shards install — this will automatically build the native library.

Usage

require "css-inline"

# Inline CSS from <style> tags
html = "<html><head><style>h1 { color: blue; }</style></head><body><h1>Hello</h1></body></html>"
result = CssInline.inline(html)
# => <html><head></head><body><h1 style="color: blue;">Hello</h1></body></html>

# Inline a CSS fragment
result = CssInline.inline_fragment("<h1>Hello</h1>", "h1 { color: blue; }")
# => <h1 style="color: blue;">Hello</h1>

Options

inliner = CssInline::CSSInliner.new(
  keep_style_tags: true,
  extra_css: "h1 { font-size: 2em; }",
  minify_css: true,
)

result = inliner.inline(html)

All available options:

Option	Default	Description
`inline_style_tags`	`true`	Inline CSS from `<style>` tags
`keep_style_tags`	`false`	Keep `<style>` tags after inlining
`keep_link_tags`	`false`	Keep `<link>` tags after inlining
`keep_at_rules`	`false`	Keep `@media` and other at-rules
`load_remote_stylesheets`	`true`	Fetch and inline remote stylesheets
`minify_css`	`false`	Minify the inlined CSS
`remove_inlined_selectors`	`false`	Remove selectors that were inlined
`apply_width_attributes`	`false`	Set `width` HTML attributes from CSS
`apply_height_attributes`	`false`	Set `height` HTML attributes from CSS
`base_url`	`nil`	Base URL for resolving relative URLs
`extra_css`	`nil`	Additional CSS to inline
`cache`	`nil`	Stylesheet cache (see below)

Stylesheet Cache

Reuse parsed stylesheets across multiple calls:

cache = CssInline::StylesheetCache.new(size: 64)
inliner = CssInline::CSSInliner.new(cache: cache)

inliner.inline(html1)
inliner.inline(html2) # reuses cached stylesheets

Contributing

Fork it (https://github.com/osbre/css-inline/fork)
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create a new Pull Request

Contributors

Ostap Brehin - creator and maintainer

css-inline

Installation

shard.yml

Dependencies

README

css-inline

Prerequisites

Installation

Usage

Options

Stylesheet Cache

Contributing

Contributors

Documentation

Links

This branch

Dependents

Repository

Metadata