The Best Ghost Themes for Documentation Sites in 2026

If you're building a documentation site on Ghost CMS, your theme options are thin. Most documentation tools (GitBook, ReadTheDocs, Docusaurus) aren't Ghost themes. Most Ghost themes aren't built for documentation. They're built for blogs.

That leaves you with three choices: hack a blog theme into something that vaguely resembles docs, build a custom theme from scratch, or find a Ghost documentation theme that was designed for the job. Here's how the options compare in 2026.

What a documentation site actually requires

Documentation is not a blog. The content structure is hierarchical, not chronological. Readers navigate by section, not by date. A docs site needs:

• Sidebar navigation - persistent, collapsible, organized by section with active state highlighting
• Table of contents - per-page, tracking the reader's position as they scroll
• Breadcrumbs - showing where the reader is in the hierarchy
• Previous / Next navigation - sequential movement through docs
• Code blocks with copy buttons - syntax highlighting, language labels, one-click clipboard copy
• Reading progress indicator - especially important for long API reference pages

None of this exists in Ghost's default themes. Not in Casper. Not in Source.

Casper and Source: what they give you

Casper is Ghost's default theme. Clean, fast, three layout options. It's a solid blog theme. But it has no sidebar navigation, no table of contents, no breadcrumbs, no code copy buttons, and no reading progress bar. Your documentation would display as a reverse-chronological feed of posts. That's the wrong pattern for docs.

Source is Ghost's modern default. More customizable - five header styles, a sidebar option, featured posts strip. Better than Casper for a publication, but still fundamentally a blog theme. The sidebar shows publication info, not document navigation. There's no TOC, no prev/next, no code copy buttons.

Both themes render documentation as blog posts. That might technically work. It doesn't work well.

Codex: a Ghost documentation theme built for the job

Codex was built specifically as a Ghost documentation theme. Every design decision assumes the content is technical documentation, not blog posts.

The layout is three columns: left sidebar for section navigation, main content area, and a right-hand "On this page" table of contents. The sidebar is collapsible, organized by tag (each tag becomes a section, each post becomes a page), with active state highlighting so readers always know where they are.

The right sidebar generates a TOC automatically from headings on the current page, with scroll-spy that highlights the current section as you read. Breadcrumbs appear on every doc page showing the full path. Previous and Next links appear at the bottom of every page for sequential navigation.

Code blocks ship with syntax highlighting, language labels, and a copy-to-clipboard button. The typography is IBM Plex Sans for body text and IBM Plex Mono for code - a stack designed for technical readability.

Feature comparison: Codex vs. Casper vs. Source

Feature	Codex	Casper	Source
Sidebar section navigation	Yes	No	No
Table of contents (per page)	Yes	No	No
Breadcrumbs	Yes	No	No
Prev / Next doc navigation	Yes	No	No
Reading progress bar	Yes	No	No
Code copy button	Yes	No	No
Custom sign-in page (not Portal)	Yes	No	No
Custom sign-up page with pricing	Yes	No	No
Callout components (Tip/Warning)	Yes	No	No
Dark mode	Yes	Yes	No

The membership layer matters too

If you're gating documentation behind a subscription - paid API docs, premium tutorials, internal knowledge bases - the membership flow matters. Casper and Source use Ghost Portal, which is a modal overlay. It works, but it looks generic.

Codex ships custom sign-in and sign-up pages. Full-page, on-brand flows. The sign-up page shows your pricing tiers inline. Navigation adapts based on membership state - different views for logged-out visitors, free members, and paid subscribers.

Who this setup works for

Codex on Ghost makes sense for SaaS companies documenting an API who want to own their content and avoid per-seat SaaS pricing from GitBook or ReadMe. It works for developer tools with a technical writer audience. For indie developers shipping documentation alongside a paid product. For teams already on Ghost who want to add a docs section without a separate platform.

Where it doesn't work: if you need versioned documentation (Ghost doesn't version content), or complex multi-product documentation hierarchies with hundreds of pages. Those use cases need a dedicated docs platform.

Getting started

Codex is a standard Ghost theme. Install it like any other. Create tags for sections, posts for pages, configure nav in Ghost admin. The membership pages handle themselves once you set up tiers in Ghost.

$79, one-time purchase, self-hosted. See the demo or view the theme page.