---
layout: docs
title: Front Matter
permalink: /docs/frontmatter/
---

The front matter is where Jekyll starts to get really cool. Any file that
contains a [YAML](http://yaml.org/) front matter block will be processed by
Jekyll as a special file. The front matter must be the first thing in the file
and must take the form of valid YAML set between triple-dashed lines. Here is a
basic example:

```yaml
---
layout: post
title: Blogging Like a Hacker
---
```

Between these triple-dashed lines, you can set predefined variables (see below
for a reference) or even create custom ones of your own. These variables will
then be available to you to access using Liquid tags both further down in the
file and also in any layouts or includes that the page or post in question
relies on.

<div class="note warning">
  <h5>UTF-8 Character Encoding Warning</h5>
  <p>
    If you use UTF-8 encoding, make sure that no <code>BOM</code> header
    characters exist in your files or very, very bad things will happen to
    Jekyll. This is especially relevant if you’re running
    <a href="../windows/">Jekyll on Windows</a>.
  </p>
</div>

<div class="note">
  <h5>ProTip™: Front Matter Variables Are Optional</h5>
  <p>
    If you want to use <a href="../variables/">Liquid tags and variables</a>
    but don’t need anything in your front matter, just leave it empty! The set
    of triple-dashed lines with nothing in between will still get Jekyll to
    process your file. (This is useful for things like CSS and RSS feeds!)
  </p>
</div>

## Predefined Global Variables

There are a number of predefined global variables that you can set in the
front matter of a page or post.

<div class="mobile-side-scroller">
<table>
  <thead>
    <tr>
      <th>Variable</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>
        <p><code>layout</code></p>
      </td>
      <td>
        <p>

          If set, this specifies the layout file to use. Use the layout file
          name without the file extension. Layout files must be placed in the
          <code>_layouts</code> directory.

        </p>
      </td>
    </tr>
    <tr>
      <td>
        <p><code>permalink</code></p>
      </td>
      <td>
        <p>

          If you need your processed blog post URLs to be something other than
          the site-wide style (default <code>/year/month/day/title.html</code>), then you can set
          this variable and it will be used as the final URL.

        </p>
      </td>
    </tr>
    <tr>
      <td>
        <p><code>published</code></p>
      </td>
      <td>
        <p>
          Set to false if you don’t want a specific post to show up when the
          site is generated.
        </p>
      </td>
    </tr>
  </tbody>
</table>
</div>


## Custom Variables

Any variables in the front matter that are not predefined are mixed into the
data that is sent to the Liquid templating engine during the conversion. For
instance, if you set a title, you can use that in your layout to set the page
title:

```html
<!DOCTYPE HTML>
<html>
  <head>
    <title>{% raw %}{{ page.title }}{% endraw %}</title>
  </head>
  <body>
    ...
```

## Predefined Variables for Posts

These are available out-of-the-box to be used in the front matter for a post.

<div class="mobile-side-scroller">
<table>
  <thead>
    <tr>
      <th>Variable</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>
        <p><code>date</code></p>
      </td>
      <td>
        <p>
          A date here overrides the date from the name of the post. This can be
          used to ensure correct sorting of posts. A date is specified in the
          format <code>YYYY-MM-DD HH:MM:SS +/-TTTT</code>; hours, minutes, seconds, and timezone offset
          are optional.
        </p>
      </td>
    </tr>
    <tr>
      <td>
        <p style="margin-bottom: 5px;"><code>category</code></p>
        <p><code>categories</code></p>
      </td>
      <td>
        <p>

          Instead of placing posts inside of folders, you can specify one or
          more categories that the post belongs to. When the site is generated
          the post will act as though it had been set with these categories
          normally. Categories (plural key) can be specified as a <a
          href="https://en.wikipedia.org/wiki/YAML#Basic_components">YAML list</a> or a
          space-separated string.

        </p>
      </td>
    </tr>
    <tr>
      <td>
        <p><code>tags</code></p>
      </td>
      <td>
        <p>

          Similar to categories, one or multiple tags can be added to a post.
          Also like categories, tags can be specified as a <a
          href="https://en.wikipedia.org/wiki/YAML#Basic_components">YAML list</a> or a
          space-separated string.

        </p>
      </td>
    </tr>
  </tbody>
</table>
</div>

<div class="note">
  <h5>ProTip™: Don't repeat yourself</h5>
  <p>
    If you don't want to repeat your frequently used front matter variables
    over and over, just define <a href="../configuration/#front-matter-defaults" title="Front Matter defaults">defaults</a>
    for them and only override them where necessary (or not at all). This works
    both for predefined and custom variables.
  </p>
</div>
