
Ace is a documentation theme built for projects that outgrow a single README. When a product reaches the point where onboarding instructions, API references, and troubleshooting guides all compete for attention in one file, Ace provides the structural spine to separate those concerns into individually addressable pages with consistent navigation.
This overview covers the anatomy of the theme, the content hierarchy it enforces, where it genuinely helps, and where it can introduce unnecessary overhead. If you have built documentation sites before and found that the navigation fell apart once you crossed thirty pages, the design decisions here will feel familiar.
The Ace layout divides the screen into three functional zones: a persistent sidebar, the content pane, and a top bar that houses search and global controls. Each zone has a specific job and intentionally avoids duplicating what the others do.
The sidebar is a grouped, scrollable list of links organized by section. Each section has a heading and a flat list of child pages. Ace does not support infinite nesting in the sidebar because deeply nested trees create more confusion than they solve. Two levels of hierarchy cover the majority of documentation structures. If you need a third level, it belongs inside the content pane as anchor links or a local table of contents, not as another tier in the sidebar.
The content pane is where documentation text, code samples, tables, and media live. Ace applies a prose-optimized typographic scale to this area. Line lengths stay within 65 to 80 characters on desktop viewports. Headings follow a strict descending order from h2 through h4 inside each page. The h1 is reserved for the page title and appears exactly once.
The top bar holds the site name, a global search input, and optional links to external resources like a GitHub repository or a changelog. It stays fixed at the top of the viewport so that search is always one click away.
Ace enforces a content model that separates pages into four types. Understanding these types helps you plan your documentation structure before you start writing.
Not every documentation site needs all four types from day one. Start with overview and how-to pages, then add reference and troubleshooting pages as the product matures.
A dedicated documentation theme is the right choice when your content meets at least two of these criteria:
If you have three pages of documentation and a predictable audience, a simple static page or even a well-organized README will serve you better. Reaching for a full theme at that scale adds navigation overhead that the content does not justify.
Documentation themes introduce friction when they are applied to content that does not need persistent navigation. A single-page guide, a FAQ with ten entries, or a product changelog are all examples where the sidebar and section grouping add visual noise without improving discoverability.
Another common failure mode is creating too many pages with too little content per page. If a page has fewer than 200 words, it probably belongs as a section within a larger page rather than as a standalone entry in the sidebar. Ace works best when each page represents a self-contained topic that a reader might bookmark or link to independently.
A typical Ace-powered documentation site might organize its sidebar like this:
Each section heading groups three to six pages. If a section grows beyond eight pages, consider splitting it into two sections. If it has only one page, consider merging it into a related section.
Readers who arrive at a documentation site expect search to work instantly and return relevant results from page titles, headings, and body text. Ace is designed with search as a first-class navigation method. The search input in the top bar is always visible, and results are displayed in a dropdown overlay so the reader does not lose their current context.
For search to be effective, your content needs clear headings, descriptive page titles, and consistent terminology. Avoid using different words for the same concept across pages. If you call something a "component" on one page and a "widget" on another, search results become fragmented and harder to scan.
Ace includes a set of shortcode-style content helpers for callouts, tabs, notes, and other structured content blocks. These helpers keep your documentation visually consistent without requiring custom CSS on every page. For a detailed reference with examples, see the Ace Shortcodes documentation.
If you are evaluating Ace for a new documentation project, start by mapping out your sidebar structure and identifying which content types you need. Review the shortcodes page to understand the content helpers available, and explore the full documentation themes catalog to compare Ace with other options.