Gutenberg Block Development: A Beginner’s Guide to Building Custom WordPress Blocks

Updated on Oct 13, 2025

7 min read

Introduction

In this comprehensive guide, we’ll explore Gutenberg Block Development, empowering WordPress developers and enthusiasts to create custom, reusable blocks. With basic knowledge of HTML, CSS, and JavaScript, you can follow along and build effective, editor-friendly content components. We’ll navigate through the essential concepts of block development, including setup, coding specifics, and best practices to ensure your blocks are maintainable and secure.

What This Guide Covers

The significance of Gutenberg blocks and when to implement them
The structure of a block (block.json, editor JS, PHP registration, styles)
A practical guide to scaffold a plugin, code the editor and front-end, and utilize @wordpress/scripts
Advanced features: dynamic blocks, media handling, and InnerBlocks
Best practices for testing, security, accessibility, and distribution

Who This Guide Is For

This guide is ideal for WordPress developers new to the Block Editor, theme and plugin authors seeking reusable UI components, and front-end developers experienced in modern JavaScript wanting to integrate with WordPress.

Understanding Gutenberg Blocks

Gutenberg, the Block Editor introduced in WordPress, revolutionizes how content is created by using modular blocks. This method allows for rich UI elements and efficient content management through reusable components that plugins or themes can register. Learning Gutenberg block development equips you to create components that enhance editor usability, portability, and maintainability.

Blocks vs. Classic Editor Content

Classic Editor: Content is stored as unstructured HTML, making it challenging to manage and reuse.
Block Editor: Content is structured as JSON-like block markup within post_content, allowing easier processing and rendering.

Types of Blocks

Static (Client-Rendered) Blocks: Save their final HTML using the save() function in JavaScript, requiring no PHP processing.
Dynamic (Server-Rendered) Blocks: These use a render_callback in PHP to generate output based on user-specific or time-sensitive data. The block.json metadata standard simplifies registration and works seamlessly with register_block_type_from_metadata in PHP.

Setting Up Your Development Environment

Local WordPress

To develop effectively, set up a local WordPress environment using:

LocalWP: Recommended for its user-friendly interface
XAMPP / MAMP: Popular cross-platform options
Docker: For containerized stacks
WSL on Windows: Useful for running Linux tools

For WSL setup, check this guide: Installing WSL on Windows. For configuring WSL with PHP, Composer, and Node, refer to this guide: WSL Configuration Guide.

Node.js & Build Tooling

Ensure you have Node.js LTS and npm (or Yarn) installed. Utilize @wordpress/scripts to maintain simplicity in building blocks without complex Webpack configurations.

Code Editor and Development Tools

VS Code: Highly recommended with ESLint and Prettier plugins.
Browser Dev Tools: Essential for debugging the editor interface.

Plugin vs. Theme Development

For optimal portability and reusability, develop blocks within a plugin rather than within a theme. Explore these guides for setting up robust Docker stacks: Windows Containers Docker Integration Guide and Container Networking for Beginners.

Anatomy of a Gutenberg Block

A standard block project encompasses:

block.json: Metadata detailing the block’s name, title, category, attributes, and assets
src/index.js: Editor entry point containing edit and save functions
src/editor.scss and src/style.scss: Separate styles for the editor and the front-end
PHP bootstrap: plugin file for block registration
build/ folder: Compiled assets from @wordpress/scripts build

block.json Structure

The block.json file serves to describe the block to WordPress and the build tools. Key fields include:

name: Unique identifier for the block
title: Human-readable label
category: Category of the block (e.g., layout, widgets)
icon: Dashicon or SVG representation
attributes: Definitions for block attributes (e.g., text, boolean)
editorScript, script, style, editorStyle: Asset handles established during the build process

Editor Code

Utilizing WordPress packages globally available in the editor or resolved through @wordpress/scripts, your editor JS code may resemble:

import { registerBlockType } from '@wordpress/blocks';
import { useBlockProps, RichText, InspectorControls } from '@wordpress/block-editor';
import { PanelBody, TextControl } from '@wordpress/components';
import { __ } from '@wordpress/i18n';

registerBlockType('my-plugin/simple-quote', {
  edit: ({ attributes, setAttributes }) => {
    const blockProps = useBlockProps();
    return (
      <div {...blockProps}>
        <InspectorControls>
          <PanelBody title={__('Quote Settings', 'my-plugin')}>
            <TextControl
              label={__('Author', 'my-plugin')}
              value={attributes.author}
              onChange={(author) => setAttributes({ author })}
            />
          </PanelBody>
        </InspectorControls>

        <RichText
          tagName="blockquote"
          value={attributes.quote}
          onChange={(quote) => setAttributes({ quote })}
          placeholder={__('Write quote...', 'my-plugin')}
        />

        <RichText
          tagName="cite"
          value={attributes.author}
          onChange={(author) => setAttributes({ author })}
          placeholder={__('Author name', 'my-plugin')}
        />
      </div>
    );
  },
  save: ({ attributes }) => {
    const blockProps = useBlockProps.save();
    return (
      <blockquote {...blockProps}>
        <RichText.Content tagName="blockquote" value={attributes.quote} />
        {attributes.author && <cite>{attributes.author}</cite>}
      </blockquote>
    );
  }
});

Build Scripts with @wordpress/scripts

Add the following to your package.json:

{
  "scripts": {
    "start": "wp-scripts start",
    "build": "wp-scripts build"
  },
  "devDependencies": {
    "@wordpress/scripts": "^27.0.0"
  }
}

Run npm run start to initiate a development server with hot reload capabilities.
Execute npm run build to create production-ready assets within the build/ directory.

PHP Registration

In your main plugin file, include:

<?php
/**
 * Plugin Name: My Block Plugin
 */

defined('ABSPATH') || exit;

function my_block_plugin_register() {
    register_block_type_from_metadata(__DIR__ . '/build');
}
add_action('init', 'my_block_plugin_register');

Component Integration

To enable functionality: 1. Create src files and block.json; 2. Run npm install followed by npm run build to generate assets inside build/; 3. Activate your plugin in WordPress—the block will now be visible in the Block Editor.

Enhancing Your Block with Interactivity and Advanced Features

Managing Attributes

Use attributes to preserve data across editor refreshes, saves, and the front end.
Implement component state (useState) for ephemeral UI elements.

Dynamic Blocks

For blocks relying on real-time data (e.g., user information, external APIs), create a server-rendered block with a render_callback. Example:

function my_dynamic_block_render($attributes) {
    $time = current_time('mysql');
    return sprintf('<div class="my-dynamic">%s — %s</div>', esc_html($attributes['message']), esc_html($time));
}

register_block_type(__DIR__ . '/build', [
    'render_callback' => 'my_dynamic_block_render',
]);

Common Editor Components

Utilize components like MediaUpload, InspectorControls, and InnerBlocks for added interactivity in your blocks.

Styling Your Blocks

Editor vs. Front-End Styles

Apply the editorStyle for styles within the editor and style for front-end presentation. When utilizing SASS, ensure proper compilation within your build process—@wordpress/scripts supports .scss file imports.

Scoped Styles

Avoid global styles by implementing useBlockProps(). This method guarantees consistent class names and attributes, and keeps styling localized to the block class to minimize conflicts.

Testing, Debugging, and Best Practices

Debugging Techniques

Inspect props and state using the browser console during the editor phase. Utilize options within the block editor to diagnose behaviors.

Linting and Formatting

Integrate ESLint and Prettier through @wordpress/scripts for consistent code quality and formatting.

Accessibility and Security Practices

Ensure all interactive controls are keyboard-accessible, use __() for translations, and sanitize outputs in PHP with functions like esc_html, wp_kses, and esc_url.

Publishing and Distribution

Preparing Your Block for Distribution

Follow WordPress.org guidelines for packaging your plugin, complete with a readme file and versioning to facilitate updates. Maintain a clear changelog and facilitate collaborations through platforms like GitHub.

Next Steps and Resources

As you progress, consider delving into advanced JavaScript topics, REST API integration for dynamic content, and exploring community libraries. For impactful learning:

Review the Gutenberg GitHub repository for practical examples.
Follow the Create a Gutenberg Block tutorial for hands-on learning.

Community Support

Engage with active communities such as WordPress StackExchange, Gutenberg GitHub Discussions, and Make/Core Slack channels to ask questions and connect.

Conclusion & Quick Checklist

In this guide, you’ve explored the structure and development of Gutenberg blocks. You’ve learned how to create your first block and incorporated best practices to ensure security and accessibility. Here’s your quick checklist:

Set up a local WordPress environment (LocalWP / Docker / WSL)
Install Node.js and npm
Scaffold your plugin with a block.json and src/ directory
Implement edit() and save() functions (or PHP render_callback)
Build your assets and verify the build/ folder
Register your block with PHP using register_block_type_from_metadata
Test your block’s editor and front-end; sanitize and escape outputs
Compile your readme, versioning, and prepare for publication