How a Jekyll Blog Works Behind the Scenes
What Actually Powers a Jekyll Blog on GitHub Pages?
To truly master your Jekyll-powered blog hosted on GitHub Pages, you first need to understand the internal workings of this static site setup. Many users install a Jekyll theme like Mediumish and jump straight into content creation, but having a strong foundational understanding of the underlying stack can save hours of confusion later—especially when customizing layouts, adding new features, or troubleshooting.
Why Jekyll Is Ideal for GitHub Pages
Jekyll is a static site generator built in Ruby that transforms plain text files into websites. When paired with GitHub Pages, Jekyll becomes a powerful engine for bloggers and developers who want version-controlled, fast-loading sites without needing a traditional CMS or web server.
Main Reasons It's Widely Used:
Free Hosting: GitHub Pages hosts your Jekyll site at no cost.
No Server Required: Static files mean no backend maintenance.
Developer Friendly: Markdown, Liquid templating, and Git integration offer full control.
How Does Jekyll Transform Content into a Website?
At the core, Jekyll takes content written in Markdown or HTML, uses Liquid templates to structure it, and outputs a complete static HTML website. This process is triggered either locally via command line or automatically when pushed to GitHub if GitHub Pages is configured correctly.
Key Components in the Stack
Understanding the moving parts is key to mastering Jekyll:
1. _config.yml
This file holds your site’s configuration settings, including theme, base URL, plugin usage, and more. Any global behavior for your site begins here.
2. _layouts/ and _includes/
Layouts wrap your content. Includes are small reusable components like headers and footers that can be dropped into layouts or content files.
3. _posts/
Each file in this folder is treated as a blog post. The naming format (YYYY-MM-DD-title.md) determines the URL structure and post publishing order.
4. _data/
This folder contains YAML, JSON, or CSV files that act like mini databases, allowing you to reuse structured data across your site without hardcoding.
5. _site/
This is the final output folder created by Jekyll. It contains the compiled HTML version of your site and is what GitHub Pages serves.
What Role Does the Mediumish Theme Play?
The Mediumish theme is a design layer built with Jekyll in mind. It sits on top of the Jekyll engine and controls how content is presented. Think of it like a WordPress theme—defining typography, layout, and visual hierarchy—but with far more flexibility for developers.
Key Features of Mediumish:
Modern Look: Medium-inspired, clean, and responsive.
Grid Layout: Uses cards for post previews and image thumbnails.
Navigation & Search: Easily customizable header and search integration.
What Happens When You Push Code to GitHub?
Once you push your Jekyll-powered blog repository to GitHub, the Pages feature will detect the configuration and automatically build your site. This process uses GitHub's Jekyll build environment, which reads your theme, Markdown files, and configuration, then publishes the static files to your https://username.github.io domain.
What GitHub Pages Actually Does:
Reads your repository for Jekyll-compatible structure.
Compiles Markdown and Liquid templates using its Jekyll engine.
Publishes the result to your GitHub Pages domain.
What Are Common Problems Beginners Face?
While GitHub Pages and Jekyll make blogging simple in theory, several common issues arise:
1. Site Not Updating
This usually happens when you forget to push your changes or when the build process fails due to YAML errors or unsupported plugins.
2. URLs Breaking
If baseurl or permalink settings in _config.yml are misconfigured, internal links and resources may break.
3. Assets Not Loading
This occurs when referencing local assets without correctly setting the path according to the base URL or theme folder structure.
How to Safely Customize Mediumish Without Breaking It
Mediumish is highly customizable, but beginners often overwrite the theme’s files directly, which makes upgrading difficult. The best practice is to:
Use the
_includesand_layoutsfolders to override theme components without touching the core theme.Copy the theme locally rather than relying on the remote
gem-basedversion if you plan heavy customization.Use Git branches to experiment with changes before deploying to your main branch.
How Can You Extend Functionality with Plugins?
Jekyll plugins can add advanced features like sitemaps, RSS feeds, and tag pages. However, GitHub Pages only supports a limited set of plugins by default. To go beyond these, you’ll need to build the site locally using bundle exec jekyll build and push the generated _site/ folder to a separate branch (usually gh-pages).
Common Plugins for Blogs:
jekyll-seo-tag: For better meta tags and OpenGraph support.jekyll-feed: Automatically generates RSS feeds.jekyll-sitemap: Generates a search-engine-friendly sitemap.xml.
Can You Use Jekyll Without Knowing Ruby?
Absolutely. While Jekyll is built in Ruby, most users can build full sites without touching any Ruby code. Knowing Liquid (Jekyll’s templating language), HTML, and Markdown is sufficient for 90% of use cases.
What’s the Learning Curve Like for Beginners?
If you’ve never used static site generators before, expect a moderate learning curve. However, the payoff is significant: blazing fast load times, full control over layout, and no reliance on databases or admin panels.
Recommended Learning Steps:
Start by modifying content in
_postsandindex.html.Move on to tweaking layout files to change your homepage.
Dive into
_config.ymlto add navigation, search, and metadata.
How Do You Know If This Stack Is Right for You?
If you prefer minimalism, speed, and version control, then Jekyll with GitHub Pages and a theme like Mediumish is ideal. It’s not for everyone—dynamic features like comments or user accounts are harder to implement—but for most blogs and documentation sites, it’s a perfect fit.
Final Thoughts
A Jekyll blog running Mediumish on GitHub Pages may seem like magic, but once you break it down, it's simply a smart combination of templates, configuration files, and Markdown. Understanding what goes on behind the scenes gives you confidence and flexibility to build and maintain a professional-quality blog without touching a traditional CMS.