Front Matter Data

Contents

Template Configuration
Sources of Data
Front Matter Formats
From the Community

Add data in your template front matter, like this:

Syntax YAML

---
title: My page title
---

<!doctype html>
<html>
…

The above is using YAML syntax. You can use other formats too.

Locally assigned front matter values override things further up the layout chain. Note also that layouts can contain front matter variables that you can use in your local template. Leaf template front matter takes precedence over layout front matter. Read more about Layouts.

Note that only the permalink and eleventyComputed front matter values can contain variables and shortcodes like you would use in the body of your templates. If you need to use variables or shortcodes in other front matter values, use eleventyComputed to set them.

Template Configuration

Eleventy allows many options to control how your template works. The most popular is permalink, which allows you to change where the file goes on the file system. You can set these options in your front matter, or anywhere else in the Data Cascade. Read more about Template Configuration.

Sources of Data

When the data is merged in the Eleventy Data Cascade, the order of priority for sources of data is (from highest priority to lowest):

Front Matter Formats

Eleventy uses the gray-matter package for front matter processing. gray-matter (and thus, Eleventy) includes support out of the box for yaml, json, and js front matter (with some aliases also included).

Change the default format project-wide

By default, yaml is used when a front matter syntax is not explicitly specified. You can change this project-wide with:

eleventy.config.js

ESM CommonJS

export default function (eleventyConfig) {
	eleventyConfig.setFrontMatterParsingOptions({
		language: "js", // default is "yaml"
	});
};

module.exports = function (eleventyConfig) {
	eleventyConfig.setFrontMatterParsingOptions({
		language: "js", // default is "yaml"
	});
};

JSON Front Matter

---json
{
  "title": "My page title"
}
---

<!DOCTYPE html>
<html>
	…
</html>

JavaScript Front Matter

Added in v3.0.0You can use any arbitrary JavaScript here and we’ll export all of the top level variables and functions to your template. This uses the node-retrieve-globals library.

Syntax Nunjucks

---js
const title = "My page title";

function currentDate() {
	return (new Date()).toLocaleString();
}
---

<h1>{{ title }}</h1>
<p>Published on {{ currentDate() }}</p>

Warning: while Nunjucks and Liquid syntax are similar, the above example will not work in Liquid. Liquid does not allow function execution in output (e.g. {{ currentDate() }}).

More Advanced Examples of JavaScript Front Matter

---js
// async-friendly
const myAsyncString = await Promise.resolve("HELLO FROM THE OTHER SIDE");

// export via destructuring assignment
const { myKey } = { myKey: "myValue" };
const [ first, second ] = [ "first", "second" ];

// export via dynamic import
const { noop } = await import("@zachleat/noop");

// access Node.js globals like console.log
console.log({ noop });
---
<!-- The template content goes here -->

JavaScript Object Front Matter

In previous versions of Eleventy, js front matter was required to use a JavaScript object notation. This method is still supported moving forward.

Syntax Nunjucks

---js
{
  title: "My page title",
  currentDate: function() {
    // You can have a JavaScript function here!
    return (new Date()).toLocaleString();
  }
}
---

<h1>{{ title }}</h1>
<p>Published on {{ currentDate() }}</p>

Warning: while Nunjucks and Liquid syntax are similar, the above example will not work in Liquid. Liquid does not allow function execution in output (e.g. {{ currentDate() }}).