Jekyll creates variables for Liquid from three locations:

1. Your site's _config.yml file (read more)
2. Other yml files in the _data folder (read more)
3. YAML Front Matter in any other file (read more)

Which means in addition to the standard variables, you can specify your own.

Site Variables

The site variable is the root object for the site, represented as a Ruby hash. This is a very large object since it contains the entire site, its meta data, and other build-time artifacts, but here are some interesting variables from this site:

Data Variables

The data variable is the union of all of the yml files in the _data folder and is accessible from the site variable. Each yml file adds another object with the same name as its source file. If there are no data files, then this object is empty.

On this site, I use ghpaghes-ghcomments and tags, and each has its own file: gpgc.yml and tags.yml. Here are some interesting variables from them:

Note (May 2026)

Notice that site.data.tags[0] is empty… But how are there still tags under the post titles?

This blog began with a theme that didn't support Jekyll tags, so I added support with a (clunky) custom clump of bash and liquid scripts paired with nested include templates.

Today's theme has support for tags and Jekyll gives access to them in two ways.

Variable	Contents	Origin
site.tags	GitHub Pages, Jekyll, Liquid,	Jekyll
page.tags	GitHub Pages, Jekyll, Liquid	Jekyll

Page Variables

The page variable is the object for a page. Often, the variable is renamed to post by layout or include files. Here are interesting variables from this page: