Gutenberg is the default content editor in WordPress. It was introduced in WordPress 5.0, released in December 2018, replacing the Classic Editor that had been the standard for over a decade. The name is a nod to Johannes Gutenberg, the inventor of the printing press. The core idea is straightforward: instead of a single text area where you format everything inline, every piece of content is its own "block" that you can move, configure, and style independently.
The History Behind Gutenberg
Before Gutenberg, WordPress used TinyMCE, a classic WYSIWYG (What You See Is What You Get) rich-text editor. TinyMCE served WordPress well for years, but it had limitations. Adding complex layouts, like multi-column sections or styled call-to-action boxes, typically required shortcodes, custom HTML, or page builder plugins. The WordPress core team started the Gutenberg project in 2017 with the goal of making rich content creation accessible to everyone, not just developers or users willing to install third-party page builders. When WordPress 5.0 shipped in December 2018, Gutenberg became the default editor for all new posts and pages.
How the Block Editor Works
Everything in Gutenberg is a block. A paragraph is a block. An image is a block. A heading, a list, a video embed, a button, a table; all blocks. You build a page by stacking these blocks vertically and configuring each one through its own toolbar and settings panel. Blocks can be rearranged by dragging them or using the up/down arrows. Each block stores its content and configuration as a combination of HTML and special HTML comments that WordPress uses to reconstruct the block in the editor.
Block Categories and Types
WordPress ships with dozens of built-in blocks, organized into categories:
- Text blocks: Paragraph, Heading, List, Quote, Code, Preformatted, Pullquote, Verse, Table.
- Media blocks: Image, Gallery, Audio, Video, Cover, File, Media & Text.
- Design blocks: Columns, Group, Row, Stack, Separator, Spacer, Buttons, Details.
- Widget blocks: Latest Posts, Latest Comments, Archives, Categories, Page List, Search, Tag Cloud, Social Icons, Calendar.
- Embed blocks: YouTube, Vimeo, Twitter/X, Spotify, SoundCloud, TikTok, and many other oEmbed-compatible services.
Reusable Blocks and Block Patterns
Reusable blocks (now called "Synced Patterns" since WordPress 6.3) let you save a block or group of blocks and insert them across multiple posts or pages. When you update a synced pattern, the change propagates everywhere it is used. This is useful for elements like call-to-action sections, disclaimers, or author bio boxes that appear on many pages. Block patterns are pre-designed arrangements of blocks, for example a hero section with a background image, heading, and button. WordPress core includes built-in patterns, themes can register their own, and you can browse hundreds more in the WordPress Pattern Directory.
Full Site Editing and Block Themes
Gutenberg has expanded far beyond post content. Full Site Editing (FSE), introduced progressively from WordPress 5.9 onward, allows you to edit your entire site layout with blocks: headers, footers, sidebars, archive templates, single post templates, 404 pages, and more. To use FSE, you need a "block theme" (like the default Twenty Twenty-Four or Twenty Twenty-Five themes). Block themes replace the traditional PHP template hierarchy with HTML-based templates that use blocks. The Site Editor (Appearance > Editor) gives you a visual interface to customize every part of your site without writing any code. Traditional "classic themes" still work, but they do not support FSE.
The Classic Editor Plugin
Not everyone embraced the switch. The Classic Editor plugin was released by the WordPress team as an official way to restore the old TinyMCE editor. It is one of the most-installed WordPress plugins, with millions of active installations. WordPress originally committed to supporting the Classic Editor through 2024, and the plugin continues to work and receive updates. Many long-running sites, especially those with heavily customized TinyMCE configurations or complex shortcode-based layouts, still use it. For new sites, though, the block editor is the clear direction WordPress is heading.
Gutenberg Plugin vs WordPress Core
There is an important distinction between the Gutenberg plugin and the block editor built into WordPress core. The Gutenberg plugin is a standalone plugin available on wordpress.org that serves as a testing ground for features planned for future WordPress releases. It ships new updates roughly every two weeks and includes experimental features that are not yet stable enough for core. Once a feature matures in the plugin, it gets merged into the next major WordPress release. If you are a developer or early adopter who wants to test upcoming features, you can install the Gutenberg plugin. For most site owners, the version bundled with WordPress core is the right choice.
Performance Considerations
Gutenberg is built with React on the editor side, and it adds block-specific CSS and JavaScript to the frontend. Each block type can enqueue its own stylesheet, so a page using many different block types may load more CSS files than a page built with the Classic Editor. WordPress has worked to address this: since version 5.8, block styles are loaded per-block rather than as a single large stylesheet. Still, sites with many blocks or heavy use of third-party block plugins can end up with noticeable frontend overhead. Performance-focused site owners often combine Gutenberg with a caching plugin and a CSS optimization tool to keep load times low.
Popular Block Library Plugins
The built-in blocks cover the basics, but many site owners extend the editor with third-party block libraries for more advanced layouts and components:
- Spectra (by Brainstorm Force): Adds blocks for pricing tables, post grids, forms, countdowns, star ratings, and more. Popular with Astra theme users.
- Stackable: Offers design-oriented blocks with advanced styling options, global settings, and its own design library.
- GenerateBlocks: A lightweight plugin from the GeneratePress team. Provides just four highly flexible blocks (Container, Headline, Buttons, Grid) that can replace dozens of specialized blocks through their configuration options.
- Kadence Blocks: Includes an advanced row/layout block, icon lists, info boxes, testimonials, and a form block. Known for good performance and a generous free tier.
- CoBlocks: From GoDaddy, offering blocks for food recipes, pricing tables, social sharing, click-to-tweet, and more.
Building Custom Blocks for Developers
Developers can create custom blocks using the WordPress Block API. The official tool for scaffolding a block plugin is @wordpress/create-block, which generates the file structure, build configuration, and boilerplate code. Custom blocks are built with JavaScript (typically JSX with React) for the editor side and can render either via JavaScript or server-side PHP on the frontend. The block.json file defines metadata like the block name, category, attributes, and supported features. For developers who prefer PHP-based workflows, the Advanced Custom Fields (ACF) plugin offers ACF Blocks, which let you create custom blocks using PHP templates and ACF fields without writing any React code.
What InspectWP Checks
InspectWP detects whether your WordPress site uses the Gutenberg editor by scanning the page source for block-specific HTML comments (like <!-- wp:paragraph -->, <!-- wp:image -->, and others) as well as Gutenberg-related CSS and JavaScript files. This helps you understand whether a site has adopted the block editor or is still running the Classic Editor.