Understand and activate the WordPress Multisite

Manage several WordPress sites in isolation, this is possible. But this can quickly become complex and time-consuming: repeated updates, extensions to replicate, users to duplicate: as the number of sites increases, management becomes a subject in itself.

This is where the multisite functionality comes into play: it allows to administer several sites from a single WordPress installation, with a centralized logic. Still it is necessary to know in which cases it is relevant, and how to activate properly.

👉 In this first article, we propose a review: operation, use cases, limits to anticipate, and detailed steps to activate the multisite safely. In the second part, we will talk about operational management and good practices to make this type of network live on a daily basis.

What is a WordPress Multisite Network?

Definition of WordPress Multisite

Unlike a conventional facility that can only administer one site, the multisite creates a network of sites sharing the same database, the same WordPress files, and a centralized administration.

How does it work?

• With one installation of WordPress, tens or even hundreds of sites can be administered
• A single database contains data from all network sites
• A super administrator can manage the entire network from a single dashboard
• Each site retains its own content, users, administrators and specific settings

This architecture creates complex web ecosystems while drastically simplifying maintenance and management.

The advantages of centralised management

Simplified maintenance :

• When a new version of WordPress is available, the update is only done once for all sites in the network
• Centralized management of themes and extensions (we install them / update only once)
• Unified security monitoring and consistent deployment of security updates

Resource savings :

• Sharing WordPress source files between all sites
• Optimizing server resources
• Reduced accommodation costs
• Content sharing

User management facilitated :

• User accounts shared between sites
• Assignment of site-specific roles. A user may even have no rights on a site if it has not been added.

Best use cases for a WordPress multisite

Here are some examples of situations where this solution is particularly relevant.

1. Business network : Company with several subsidiaries, departments or brands requiring separate sites, but centralized management.
2. Educational portal Universities, schools or training organizations offering one site per class, department or institution.
3. Media network Press groups managing several publications or thematic sites.
4. Franchises : Networks of franchisees requiring sites with a common charter but localized content.
5. Complex multilingual sites : Alternative to translation plugins for sites with very different language versions.
6. SaaS Platforms : Web applications allowing each customer to have their own site or space.

❌ Conversely, multisite is not a good idea if:

• You manage less than 3 sites with very different needs.
• You need radically different themes or extensions between each site.
• The sites have very different audiences and security levels.

The multisite is particularly suitable when seeking to standardize the structure of several sites, pool resources, or establish a common foundation logic. But this is not the only option to design a website factory.

📘 To explore other approaches (differentiated management, customized platforms...), consult our White Paper on websites factories WordPress.

Enable multisite mode on WordPress

The activation of the WordPress multisite requires some technical manipulations, but the process is well documented. Let's do it again.

Technical requirements

Before you start, make sure you have:

✅ A functional WordPress installation (preferably fresh)

✅ FTP or SSH access on the server

✅ Full backup the existing site

✅ Administrator rights on WordPress installation

Important : It is strongly recommended that multisite activation be tested in a development environment before implementation in production.

Step 1: Disable extensions temporarily

Before enabling the multisite, it is recommended to disable all extensions of your WordPress installation:

1. Connect to the WordPress dashboard
2. Go to Extensions > Extensions installed
3. Select all active extensions
4. Choose « Disable » in the drop-down menu
5. Click « Apply » This step avoids potential conflicts during multisite activation.

Step 2: Edit wp-config.php file

Connect to your server via FTP or SSH and change the file wp-config.php located at the root of your WordPress installation.

Add this line before the line that contains /* C'est tout, ne touchez pas à ce qui suit ! */ :

/* Multisite */
define('WP_ALLOW_MULTISITE', true);

Save the file. This modification activates the multisite option in your WordPress dashboard.

Step 3: Configure Network

1. Refresh your WordPress dashboard
2. Go to Tools > Network Configuration
3. Choose the desired network type:
   • Subdomains : site1.mondomaine.com, site2.mondomaine.com
   • Sub-directories : mondomaine.com/site1, mondomaine.com/site2 The easiest solution to implement is the use of subdirectories. You can also use different domain names for each site
4. Define the title of the network andemail address super administrator
5. Click « Install »

Alternatively, steps 2 and 3 can be replaced by the following WP CLI controls:

• wp core multisite-convert in the case of an existing installation
• wp core multisite-install in the case of a new installation

Step 4: Finalize the installation

If you have followed steps 2 and 3, WordPress will then provide you with code to add in your files wp-config.php and .htaccess. Copy and paste exactly this code to the specified locations.

If you used WP CLI commands, the file wp-config.php was updated automatically, but not the .htaccess, you will need to add the rules below.

Example code for wp-config.php:

define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', false);
define('DOMAIN_CURRENT_SITE', 'mondomaine.com');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);

Example code for .htaccess:

RewriteEngine On
RewriteBase /
RewriteRule ^index\\.php$ - [L]
# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\\.php)$ $1 [L]
RewriteRule . index.php [L]

Step 5: Reconnection and Verification

After saving these changes:

1. Reconnect to your WordPress dashboard
2. You should see a new tab appear « My sites » in the administration bar
3. Check the menu « Network » in the dashboard

Congratulations! Your WordPress multisite network is now active. Now you can reactivate the deactivated extensions in step 1.

Conclusion

To activate a multisite network is to structure the foundations of a coherent digital ecosystem, easier to maintain and easier to evolve over time.

But this is just a first step. In the next article, we take you further: how to manage users, themes, extensions, domain names... and how to secure and optimize your multisite network as it grows.

👉 If you are exploring tracks to structure or streamline your digital ecosystem, multisite may be a relevant option – among others. To better understand the different models and choose the one that fits your organization, take a look at our White Paper "Websites factories WordPress"