“How to Build a Multipurpose FSE WordPress Theme for WooCommerce (2025 Complete Guide)”

Alok maurya October 26, 2025

Learn how to create a fully responsive, block-based multipurpose WordPress theme for WooCommerce using Full Site Editing (FSE). Step-by-step guide covering theme.json, templates, patterns, and best practices to build a modern eCommerce theme.

Introduction

The WordPress ecosystem has transformed with Full Site Editing (FSE)—a revolutionary way to design entire websites visually using blocks. For developers and entrepreneurs, this opens the door to creating powerful, multipurpose WooCommerce-ready block themes that are fast, customizable, and future-proof.

In this guide, we’ll explore how to build a multipurpose FSE WordPress theme for WooCommerce—from file structure to design philosophy, optimization, and real-world deployment. Whether you’re a freelance developer or building your brand like Kaddora Tech, this tutorial will help you master the essentials.

1. Understanding Full Site Editing (FSE)

Full Site Editing allows you to design headers, footers, sidebars, product pages, and templates visually with the Block Editor—no PHP template editing needed.

Key FSE Features

Template Parts Build reusable site sections like headers and footers.
Templates Define layouts for posts, pages, products, and archives.
Global Styles Manage typography, colors, and spacing using theme.json.
Patterns Pre-built design sections that users can insert easily.
Block Styles Custom CSS variations for default blocks.

FSE themes are lighter, modular, and fully compatible with Gutenberg and WooCommerce blocks.

2. Folder Structure of an FSE Theme

A multipurpose FSE theme follows a minimal yet organized folder hierarchy.
Here’s a sample

my-fse-woocommerce-theme/

│

├─ style.css

├─ theme.json

├─ functions.php

│

├─ templates/

│ ├─ index.html

│ ├─ single.html

│ ├─ archive.html

│ ├─ 404.html

│ ├─ page.html

│ ├─ home.html

│ └─ product.html

│

├─ parts/

│ ├─ header.html

│ ├─ footer.html

│ └─ sidebar.html

│

├─ patterns/

│ ├─ hero-section.php

│ ├─ features.php

│ ├─ testimonials.php

│ └─ call-to-action.php

│

└─ inc/

└─ block-styles.php

Every folder plays a unique role

Templates/ Defines page layouts.
Parts/ Header, footer, and reusable areas.
Patterns/ Reusable block arrangements.
theme.json Controls theme styling globally.
functions.php Registers block styles, enqueues assets, etc.

3. Setting Up style.css and theme.json

Example style.css

Theme Name: Kaddora Multipurpose FSE Theme

Theme URI: https://kaddora.com/

Author: Kaddora Tech

Author URI: https://kaddora.com/

Description: A lightweight, block-based multipurpose WooCommerce theme built for Full Site Editing.

Version: 1.0

Requires at least: 6.0

Tested up to: 6.8

License: GPL v2 or later

License URI: https://www.gnu.org/licenses/gpl-2.0.html

Text Domain: kaddora-fse

Tags: full-site-editing, woocommerce, block-theme, responsive, ecommerce

Example theme.json

This JSON file defines your design system

{

“version”: 2,

“settings”: {

“color”: {

“palette”: [

{ “slug”: “primary”, “color”: “#198754”, “name”: “Primary” },

{ “slug”: “secondary”, “color”: “#222222”, “name”: “Dark” },

{ “slug”: “accent”, “color”: “#FFD700”, “name”: “Accent” }

]

“typography”: {

“fontFamilies”: [

{ “fontFamily”: “Poppins, sans-serif”, “slug”: “poppins”, “name”: “Poppins” }

“fontSizes”: [

{ “slug”: “small”, “size”: “14px”, “name”: “Small” },

{ “slug”: “medium”, “size”: “16px”, “name”: “Medium” },

{ “slug”: “large”, “size”: “20px”, “name”: “Large” }

]

“spacing”: {

“units”: [ “px”, “em”, “rem”, “%” ]

}

“styles”: {

“typography”: { “fontFamily”: “Poppins, sans-serif”, “lineHeight”: 1.6 },

“color”: { “background”: “#ffffff”, “text”: “#111111” }

}

This approach ensures design consistency across all templates and patterns.

4. Integrating WooCommerce with FSE

To make your theme WooCommerce-compatible, include this in functions.php

add_action( ‘after_setup_theme’, function() {

add_theme_support( ‘woocommerce’ );

add_theme_support( ‘woocommerce-block-templates’ );

});

Key WooCommerce Templates

With the new WooCommerce Blocks, users can design shop pages visually

This creates a seamless, block-based eCommerce experience.

5. Creating Template Parts

Template parts are reusable across your site.

Example: parts/header.html

<!– wp: group {“layout”:{“type”: “flex”, “justifyContent”: “space-between”}} –>

<!– wp:site-title {“level”:1} /–>

<!– wp: navigation /–>

<!– wp:woocommerce/mini-cart /–>

</div>

<!– /wp:group –>

Example: parts/footer.html

<!– wp: group {“align”: “full”, “backgroundColor “: “secondary”, “textColor “: “wh ite”, “style”:{“spacing”:{“padding”:{ “top”:”20px”, “bottom”: “20px”}}}} –>

<!– wp:paragraph {“align”:”center”} –>

<!– /wp:paragraph –>

</div>

<!– /wp:group –>

These are referenced in templates using

<!– wp:template-part {“slug”:”header”} /–>

<!– wp:template-part {“slug”:”footer”} /–>

6. Building Block Patterns

Patterns let users insert pre-built layouts easily.

Example: patterns/hero-section.php

<?php

register_block_pattern(

‘kaddora/hero-section’,

array(

‘title’ => __( ‘Hero Section’, ‘kaddora-fse’ ),

‘content’ => ‘

<!– wp: cover {“url “: “path-to-image.jp g”, “dimRatio”:50,”minHeight”:400} –>

<!– wp:heading {“textAlign”:”center”} –>

<h2 class=”has-text-align-center”>Build Your Dream Store</h2>

<!– /wp:heading –>

<!– wp:buttons {“align”:”center”} –>

</div>

<!– /wp:buttons –>

</div>

<!– /wp:cover –>’

)

);

7. Optimizing Your FSE WooCommerce Theme

Performance Optimization

Accessibility

SEO Optimization

8. Adding Custom Block Styles

Enhance Gutenberg blocks visually with inline CSS

Example in inc/block-styles.php

register_block_style( ‘core/button’, [

‘name’ => ’rounded-green’,

‘label’ => __( ‘Rounded Green’, ‘kaddora-fse’ ),

‘inline_style’ => ‘

.is-style-rounded-green {

background-color: #198754;

border-radius: 50px;

padding: 12px 25px;

color: #fff;

}

‘

]);

Then load the file

require get_template_directory() . ‘/inc/block-styles.php’;

9. Testing Your Theme

Before submitting or selling

10. Packaging and Distribution

Once ready

Include Demo Previews

Add subdomains like

Each showcases a niche layout using the same multipurpose base theme.

Top 10 FAQs

What is an FSE theme in WordPress? A Full Site Editing theme lets you design your entire website using blocks—headers, footers, and templates—without coding PHP templates.
Is FSE compatible with WooCommerce? Yes, WooCommerce now fully supports block templates and product blocks, making it ideal for FSE themes.
How is an FSE theme different from a classic theme? FSE themes use HTML templates and theme.json for styling, while classic themes rely on PHP and the Customizer.
Can I build multipurpose themes with FSE? Absolutely. With patterns and global styles, you can target multiple industries using one base theme.
What tools do I need to start building? You only need WordPress 6.0+, a text editor (VS Code), and basic HTML + CSS knowledge.
Can I submit my FSE theme to WordPress.org? Yes, once it follows WordPress.org’s theme review guidelines and passes validation.
Does FSE support page builders like Elementor? FSE works natively with Gutenberg. You can use Elementor separately, but they serve different approaches.
How do I make my theme lightweight? Avoid heavy scripts, optimize CSS via theme.json, and rely on native blocks instead of custom JS.
Is theme.json mandatory? For true FSE themes, yes—it’s the core file that defines design and layout settings.
Can I use my FSE WooCommerce theme commercially? Yes. Themes under the GPL license can be sold or distributed freely, provided you retain GPL compliance.

Conclusion

The WordPress landscape is moving toward a block-first, no-code era. Building your own multipurpose FSE WooCommerce theme future-proofs your brand, reduces maintenance, and delivers unmatched customization power to users.

By leveraging theme.json, global styles, WooCommerce blocks, and clean design systems, you can create scalable, performant, and beautiful digital stores for every niche.