Jasper is a full-featured Jekyll port of Ghost's default Casper theme (v1.3.7) that turns any Jekyll site into a blog with author pages, tag pages, pagination, and a toggleable sliding sidebar.
What is Jasper?
Jasper is a Jekyll theme ported from Ghost's default Casper theme v1.3.7, inspired by an earlier port called Kasper. It runs on Jekyll 3.9.0 with Ruby 2.6.3 and is maintained by the jekyllt team on GitHub. It takes Jekyll posts, author data, and front matter as input and produces a static HTML blog with the original Casper design, plus extra pages such as author, tag, 404, and related-posts views.
What makes Jasper stand out?
- Closer to original Casper — Adds features missing from Kasper, including pagination, tag pages, a 404 page, and a toggleable sliding sidebar, bringing it near the original Ghost theme.
- Multiple author support — Author pages work out of the box since the v1.3.7 update; set each post's categories field to the author's username defined in _config.yml.
- Code syntax highlighting — Uses highlight.js (added 06.04.2016) to colorize code blocks in posts.
- Related posts view — Shows related posts on each article, added 30.10.2015.
- Google Analytics and Disqus — Built-in tracking via Google Analytics and comments via Disqus, which is not part of the original Ghost theme.
- Deployment flexibility — Supports GitHub Actions, Travis CI, or Jekyll-compatible hosts like Netlify for automated builds and publishing.
- MIT License — Released under the same MIT license as Ghost's Casper theme, so it is free to use and modify.
Who should use Jasper?
- Bloggers switching from Ghost to Jekyll — They can keep the familiar Casper look while gaining Jekyll's static-site workflow and free hosting on GitHub Pages.
- Developers building personal or multi-author blogs — They get built-in author and tag pages, syntax highlighting, and Disqus comments without writing custom templates.
- Jekyll users on GitHub Pages — They can deploy via GitHub Actions pushing the generated _site folder to the gh-pages branch, or locally with bundle exec jekyll serve.
What can you do with Jasper?
- Personal bloggers: Publish a clean, Ghost-style blog with pagination and a 404 page, hosted free on GitHub Pages.
- Multi-author teams: Set up separate author profiles and pages by mapping post categories to author usernames.
- Technical writers: Use highlight.js for code syntax highlighting and related-posts views to keep readers engaged.
How does Jasper work?
To use Jasper, clone the master branch, edit _config.yml with your site details, and run bundle exec jekyll serve locally or push to a git repository. For automated deployment, set up GitHub Actions (as in the included jekyll_build.yml) or Travis CI, which builds the site and pushes the resulting _site contents to the gh-pages branch. Netlify is also supported for CDN-based hosting.
Pricing
Jasper is free and open-source under the MIT License, the same license as the original Ghost Casper theme.
Alternatives
- Kasper — The earlier Jekyll port that inspired Jasper; fewer additional features.
- Jasper2 — A newer port of Casper version 2 by the same jekyllt team, for users who want the updated design.
- Ghost's original Casper — The reference theme, but it runs on the Ghost publishing platform rather than Jekyll.
FAQ
Is Jasper free?
Yes, Jasper is released under the MIT License, so you can use, modify, and distribute it freely, including for commercial projects, with attribution.
Does Jasper support multiple authors?
Multiple author blogs are supported out of the box since the v1.3.7 update. You need to set each post's categories field to match an author's username defined in the _config.yml file.
How do I deploy Jasper to GitHub Pages?
You can build the site with GitHub Actions (the included workflow pushes _site to the gh-pages branch), or generate it locally and push the HTML to a repository's master or gh-pages branch, depending on whether it's a user or project page.
What Jekyll and Ruby versions does Jasper use?
The project builds well with Ruby v2.6.3 and Jekyll v3.9.0, as noted in the repository's install instructions.
Does Jasper include a 404 page and tag pages?
Yes, Jasper added tag pages, author pages, a 404 page, and a toggleable sliding sidebar in its 07.02.2015 update, all of which are available in the current release.
