Eleventy Review and Features

Progressive Enhancement

Long time to interactive (TTI) is a common issue in JS-based static generators like Gatsby or Next.js. The browser needs to download, parse, and execute a big chunk of JS to hydrate the application. That comes with a cost. It ends up with TTI, and input latency increases.

On a typical website, a lot of components are not very interactive, yet they need to hydrate. React team works on partial hydration that should help solve this issue, but the ETA is not clear.

In Eleventy, you can focus on providing the essential content first and add dynamic functionality step by step. Sometimes, vanilla JavaScript and pure CSS are enough to create things like animations and sliders.

Need for speed

Good performance is an essential part of every modern website. Eleventy developers love the speed. And speed loves Eleventy. Because there is no big load of JavaScript, Eleventy websites achieve great Lighthouse results. Take a look at the leaderboards created by Zach, the author of Eleventy.

Leaderboards update every 2 weeks and display a list of best-scoring projects. Most of those are very simple personal websites. So take this with a grain of salt, i.e., it doesn't really mean Eleventy is the fastest SSG on the market. I do believe a lot of those pages would have similar scores using other static site generators.

File Structure

Can be as simple as:

└── index.md

After running command, it will turn out to:

├── _site
│   └── index.html
└── index.md

is ready to deploy the output folder. Neat, huh?

Let's try to create a simple blog. The example below is based on the official eleventy-base-blog starter.

├── .eleventy.js
├── .eleventyignore
├── _data
│   └── metadata.json
├── _includes
│   ├── components
│   │   ├── footer.njk
│   │   ├── head.njk
│   │   └── header.njk
│   └── layouts
│       ├── base.njk
│       └── post.njk
├── index.njk
└── posts
    ├── hello-world.md
    └── posts.json

Data Sources

Eleventy pulls data from multiple sources. The most straightforward one is Front Matter inside page or templates files.

---
title: Post title
author: John Doe
---

<h1>{title}</h1>
07a9a4b5-5a25-4bfb-850a-1aa80029269a

...

Fetching data from Headless CMS

Every real-life project needs some sort of CMS. Not every content team is happy with editing md files and pushing it via git.

To fetch data from API, you need to create a JS file inside folder - that way, the data will be available globally.

If you want to fetch data and use it in a specific scope you need to create a file inside template or directory folders.

module.exports = async function () {
  let response = await fetch(`https://api.domain/posts`)
  let data = await response.json()

  return data
}

Ecosystem

Eleventy does have a list of starters created mostly by the community. Cool thing is that you can see the Lighthouse scores of each started, updated daily.

Eleventy doesn't have a lot of ready to use plugins, but there are a few that add functionality like RSS, PWA, Tailwind, Table of Contents, and more.

Showcase

How to get started?

To install Eleventy globally, run the command:

npm install -g @11ty/eleventy

Next, create a folder and an file.

mkdir my-11ty-website && echo '# Hello world' > index.md

To start the Eleventy project locally, run:

eleventy --serve

Open to view your website.

Conclusion

Eleventy might be the best choice to start your adventure in the Jamstack world. It gives you flexibility and doesn't push you to learn any specific JS framework like React or Vue.