Full Site Editing (FSE) is a WordPress feature that extends the block-based Gutenberg editor beyond individual posts and pages to encompass every structural element of a website, including headers, footers, navigation menus, sidebars, and page templates.
Before FSE, the Gutenberg editor was limited to the content area of a post or page. Everything surrounding that content — the site header, the footer, the overall page layout — was controlled separately through PHP template files, the Customizer, or third-party page builders. Full Site Editing removes that boundary. With an FSE-compatible theme, also called a block theme, every part of the site becomes editable through a single visual interface called the Site Editor.
The Site Editor organizes a site around templates and template parts. A template defines the overall layout for a type of page — such as a single post, a category archive, or the front page. A template part is a reusable section of that layout, most commonly the header or footer. Both are built entirely from blocks, the same units used to compose regular page content. This consistency means that anyone already familiar with the Gutenberg editor can apply the same skills to control the full visual structure of a site.
FSE was introduced progressively in WordPress, with foundational support arriving in version 5.9 alongside the Twenty Twenty-Two theme, the first default theme built specifically as a block theme. Unlike a classic child theme, which typically relies on PHP template files and the functions.php file to modify appearance, a block theme stores its templates as HTML files containing block markup, making them editable directly inside WordPress without touching code.
A related concept within FSE is the Global Styles interface, which allows site-wide typography, color palettes, and spacing to be configured visually and stored in a theme.json file. This replaces much of what was previously handled through the Customizer or custom CSS, centralizing design decisions in one structured location.
For developers and site builders, FSE represents a significant shift in how WordPress themes are architected. For content editors and marketers, it offers a more unified and predictable editing experience. For SEO professionals, the ability to control template-level elements — such as breadcrumb placement, structured layout consistency, and heading hierarchy — directly through the editor adds a practical layer of control that previously required developer involvement.
Full Site Editing is sometimes used interchangeably with the term block editing or described under the broader umbrella of the Gutenberg project, though FSE specifically refers to the extension of that editing model to the entire site rather than just post content.