Jasper is a Jekyll blog theme that ports Ghost's default Casper theme (v1.3.7) to the Jekyll static site generator, producing a fully featured blogging site for personal or multi-author use. It is maintained by the jekyllt project on GitHub and is distributed under the MIT License.
What is Jasper?
Jasper is a Jekyll theme that recreates the design and layout of Ghost's Casper theme for Jekyll-powered static sites. It takes posts written in Markdown with YAML front matter and generates a complete blog with home, post, author, tag, related-posts, sidebar, and 404 pages. The theme runs on Jekyll 3.9 and Ruby 2.6.3, and it works out of the box with GitHub Pages, Travis CI, and Netlify deployments. The project is maintained on GitHub under the jekyllt organization.
Key Features
- Pagination — Built-in pagination for the home page, so readers can browse posts across multiple pages.
- Google Analytics — Ready-to-use Google Analytics tracking code integration for audience measurement.
- Author profiles — Displays each author's profile picture and bio on post pages and dedicated author archive pages.
- Disqus comments — Adds Disqus comments to posts, a feature not present in the original Ghost Casper port.
- Tag and author pages — Automatically generated tag archive pages and author pages (added in 2015) for content organization.
- Toggleable sliding sidebar — A sidebar that slides in and out, controllable with a toggle, adding navigation options.
- Related posts — Shows a related posts view at the end of each article (added in October 2015) to increase engagement.
- Code syntax highlighting — Uses highlight.js for code syntax highlighting, with support added in 2016.
- Multiple authors — Out-of-the-box support for multiple authors, so each writer gets their own profile page without extra setup.
- RSS feed — The feed was updated for Jekyll v3 compatibility, so subscribers keep up with new posts.
Who is it for?
Jasper is for bloggers and developers who want the polished look of Ghost's Casper theme while staying on the free and flexible Jekyll platform. It suits personal bloggers who want a clean, typographic design with minimal configuration, as well as multi-author team blogs that need individual author pages and tag archives. It is also a strong fit for developers hosting on GitHub Pages who want a turnkey theme with GitHub Actions deployment.
What can you do with Jasper?
- Personal bloggers: Publish Markdown posts and automatically get a styled blog with pagination, a 404 page, and a sliding sidebar for navigation.
- Multi-author publications: Define each author in the configuration and each contributor receives a dedicated author page listing their posts.
- Content-driven sites: Use tag pages and related posts to group articles by topic and keep readers on the site longer.
- Developers on GitHub Pages: Deploy the static site automatically via the included GitHub Actions workflow, which builds the site and pushes the output to the gh-pages branch.
How does Jasper work?
Jasper works like any Jekyll theme: you clone the repository, edit the configuration file to set your site details and author information, and then add posts as Markdown files with front matter. To preview locally, run bundle exec jekyll serve and open the generated _site folder. For production, you can deploy via GitHub Actions (the repo includes a workflow file), Travis CI with jekyll-travis, or push the _site output to a hosting service like Netlify.
Pricing
Jasper is free and open source, released under the MIT License, the same license as Ghost's Casper theme. You can use, modify, and redistribute it for personal or commercial projects without licensing fees.
Alternatives
- Casper — The original Ghost theme that Jasper ports; it runs on the Ghost CMS rather than Jekyll.
- Kasper — An earlier PHP port of Casper that inspired Jasper but lacks many of the added features.
- Jasper2 — A newer port by the same jekyllt team that updates the theme to Casper's second version.
FAQ
Is Jasper free?
Yes, Jasper is free and distributed under the MIT License. There are no costs for using the theme, and it can be used in commercial projects as well.
What Jekyll version does Jasper require?
Jasper builds well with Ruby v2.6.3 and Jekyll v3.9.0, as stated in the project documentation. The theme's GitHub Actions workflow and Travis CI configuration are set up for these versions.
Does Jasper support multiple authors?
Yes, Jasper has out-of-the-box support for multiple authors. You define each author in the configuration file, and the theme automatically generates a profile page for each one, displaying their posts.
How do I deploy Jasper?
Jasper can be deployed several ways: using the included GitHub Actions workflow that pushes to the gh-pages branch, running the site locally and uploading the _site folder to GitHub Pages, building with Travis CI, or using Jekyll-compatible hosters like Netlify.
