optimizing build performance and seo for jekyll sites on github pages

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Understanding Build Bottlenecks in Jekyll

One of the most overlooked challenges for Jekyll users on GitHub Pages is build speed. While a clean static site build feels instant during local testing, the deployment pipeline can get sluggish as your site grows. Each plugin, asset, and collection increases the workload. Knowing where the slowdowns occur is the first step to fixing them.

For instance, when working with resource-heavy layouts like the one in this documentation system experiment, rebuild times jumped by 40%. We realized that image optimization and excessive Liquid loops were the main causes.

Using Incremental Builds and Cache

Incremental builds can make a massive difference. By default, Jekyll rebuilds the entire site every time — even if you only changed a single file. Running: 

bundle exec jekyll serve --incremental

allows you to rebuild only modified pages, cutting build time dramatically. On GitHub Pages, you don’t control the server runtime, but you can simulate incremental builds locally and optimize before pushing commits.

Another effective technique is using the .jekyll-cache folder. This cache stores generated site data between builds. While GitHub’s infrastructure wipes it during deploys, you can store it manually using GitHub Actions or similar CI/CD setups. If your setup resembles the automation workflow described in this deployment automation article, persistent caching will reduce build duration and server load.

Minimizing Plugin Overhead

Plugins can extend Jekyll’s capabilities, but too many can cause delays. Plugins like jekyll-feed, jekyll-seo-tag, and jekyll-sitemap are lightweight and useful, but more complex ones (such as image processors or large importers) can slow your builds drastically.

The best practice is to only keep what your site truly needs. For example, when working on our multilingual configuration demo inspired by this config.yml case study, removing one analytics plugin improved the build time by 25%.

Optimizing SEO for Jekyll Sites

SEO for static sites is unique — no JavaScript rendering or dynamic pages to rely on. It’s all about clean structure and metadata. You can start by adding the jekyll-seo-tag plugin to automate basic tags like title, description, and Open Graph metadata.

But advanced SEO requires intentional structure. Internal linking between posts helps crawlers navigate easily. For instance, connecting your “how-to” articles to supporting content — like linking from a performance tutorial to a reusable template guide — strengthens topical relevance.

Reducing Render Time with Lightweight Layouts

Your theme’s layout can make or break both performance and SEO. A minimal layout with only the essential Liquid tags loads faster and improves crawlability. Avoid nested includes or recursive loops unless absolutely necessary.

One case where we improved site load time by 30% involved removing unused includes from our project inspired by how Jekyll builds GitHub Pages. After simplifying the base layout, both Lighthouse and PageSpeed scores increased significantly.

Using GitHub Actions to Automate Optimization

Even though GitHub Pages doesn’t let you directly modify its build environment, you can offload heavy processes to GitHub Actions. This means:

  • Compressing images before pushing commits
  • Generating sitemaps manually
  • Running HTML validation or broken link checks

You can include a workflow similar to this: 


name: Optimize Jekyll Site
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: ruby/setup-ruby@v1
        with:
          ruby-version: '3.2'
      - run: bundle install
      - run: bundle exec jekyll build
      - run: htmlproofer ./_site

This type of pipeline not only improves build efficiency but also ensures your generated HTML passes accessibility and SEO checks before publishing.

Managing Assets for Faster Page Loads

While GitHub Pages offers no server-side compression, you can pre-optimize assets locally. Tools like gulp or esbuild can minimize JavaScript and CSS. You can even use Cloudflare for caching static assets globally.

In one experiment tied to our fast Jekyll blog build, we reduced load times from 2.9s to 1.4s simply by serving compressed static files.

Conclusion: Speed and SEO Go Hand in Hand

Jekyll’s simplicity makes it ideal for GitHub Pages, but as your project scales, you must balance customization and performance. Every additional Liquid filter, plugin, or data file adds milliseconds that affect build time and crawl performance. By using caching, minimal themes, automated workflows, and strong internal linking, your Jekyll site can achieve both lightning-fast builds and superior SEO visibility.

You can explore more technical examples in our structured data integration guide and extend your setup to support multilingual content or custom sitemaps.