About GitHub Pages and Jekyll

About Jekyll

Jekyll is a static site generator with built-in support for GitHub Pages and a simplified build process. Jekyll takes Markdown and HTML files and creates a complete static website based on your choice of layouts. Jekyll supports Markdown and Liquid, a templating language that loads dynamic content on your site. For more information, see Jekyll.

Jekyll is not officially supported for Windows. For more information, see Jekyll on Windows in the Jekyll documentation.

We recommend using Jekyll with GitHub Pages. If you prefer, you can use other static site generators or customize your own build process locally or on another server. For more information, see About GitHub Pages.

Configuring Jekyll in your GitHub Pages site

You can configure most Jekyll settings, such as your site's theme and plugins, by editing your _config.yml file. For more information, see Configuration in the Jekyll documentation.

Some configuration settings cannot be changed for GitHub Pages sites.

lsi: false
safe: true
source: [your repo's top level directory]
incremental: false
highlighter: rouge
gist:
  noscript: false
kramdown:
  math_engine: mathjax
  syntax_highlighter: rouge

By default, Jekyll doesn't build files or folders that:

• Are located in a folder called /node_modules or /vendor
• Start with _, ., or #
• End with ~
• Are excluded by the exclude setting in your configuration file

If you want Jekyll to process any of these files, you can use the include setting in your configuration file.

Front matter

To set variables and metadata, such as a title and layout, for a page or post on your site, you can add YAML front matter to the top of any Markdown or HTML file. For more information, see "Front Matter" in the Jekyll documentation.

You can add site.github to a post or page to add any repository references metadata to your site. For more information, see Using site.github in the Jekyll Metadata documentation.

Themes

You can add a Jekyll theme to your GitHub Pages site to customize the look and feel of your site. For more information, see Themes in the Jekyll documentation.

You can add a theme to your site manually. For more information, see Supported themes on the GitHub Pages site and Adding a theme to your GitHub Pages site using Jekyll.

You can override any of your theme's defaults by editing the theme's files. For more information, see your theme's documentation and Overriding your theme's defaults in the Jekyll documentation.

Plugins

You can download or create Jekyll plugins to extend the functionality of Jekyll for your site. For example, the jemoji plugin lets you use GitHub-flavored emoji in any page on your site the same way you would on GitHub. For more information, see Plugins in the Jekyll documentation.

GitHub Pages uses plugins that are enabled by default and cannot be disabled:

• jekyll-coffeescript
• jekyll-default-layout
• jekyll-gist
• jekyll-github-metadata
• jekyll-optional-front-matter
• jekyll-paginate
• jekyll-readme-index
• jekyll-titles-from-headings
• jekyll-relative-links

You can enable additional plugins by adding the plugin's gem to the plugins setting in your _config.yml file. For more information, see Configuration in the Jekyll documentation.

For a list of supported plugins, see Dependency versions on the GitHub Pages site. For usage information for a specific plugin, see the plugin's documentation.

GitHub Pages cannot build sites using unsupported plugins. If you want to use unsupported plugins, generate your site locally and then push your site's static files to GitHub Enterprise Server.

Syntax highlighting

To make your site easier to read, code snippets are highlighted on GitHub Pages sites the same way they're highlighted on GitHub Enterprise Server. For more information about syntax highlighting on GitHub Enterprise Server, see Creating and highlighting code blocks.

By default, code blocks on your site will be highlighted by Jekyll. Jekyll uses the Rouge highlighter (which is compatible with Pygments). If you specify Pygments in your _config.yml file, Rouge will be used as the fallback instead. Jekyll cannot use any other syntax highlighter, and you'll get a page build warning if you specify another syntax highlighter in your _config.yml file. For more information, see About Jekyll build errors for GitHub Pages sites.

If you want to use another highlighter, such as highlight.js, you must disable Jekyll's syntax highlighting by updating your project's _config.yml file.

kramdown:
  syntax_highlighter_opts:
    disable : true

If your theme doesn't include CSS for syntax highlighting, you can generate GitHub's syntax highlighting CSS and add it to your project's style.css file.

rougify style github > style.css

Building your site locally

If you are publishing from a branch, changes to your site are published automatically when the changes are merged into your site's publishing source. If you are publishing from a custom GitHub Actions workflow, changes are published whenever your workflow is triggered (typically by a push to the default branch). If you want to preview your changes first, you can make the changes locally instead of on GitHub Enterprise Server. Then, test your site locally. For more information, see "Testing your GitHub Pages site locally with Jekyll."