WordPress: Multisite and WPML

WordPress actually has two different answers here, for two different questions, and picking the wrong one is a common, expensive mistake.

“We have several distinct sites that should share users and plugins” (several national subsidiaries with genuinely different content and design, not just a translation of the same pages) is what WordPress Multisite solves: one WordPress install running a network of separate sites, sharing a codebase and user base but not content.

wp core multisite-convert
wp site create --slug=fr --title="Example France"
wp site create --slug=de --title="Example Germany"

“We have one site that needs to exist in several languages” (the same pages, translated) is a different problem, and Multisite is the wrong tool for it: it would mean maintaining separate copies of every page by hand. That’s what a translation plugin like WPML solves instead, keeping one site with linked translations of each page:

wp plugin install sitepress-multilingual-cms --activate
wp wpml language add fr de

// getting a translated post ID for the current language
$translated_id = apply_filters('wpml_object_id', $post_id, 'post', true);

When to reach for each

Multisite when the sites genuinely differ beyond translation: different design, different content strategy, different admin teams per country. WPML when it’s truly the same site, the same content, just needing to exist in more than one language.

When it’s the wrong fit

Using Multisite as a translation tool, or using WPML to try to run what are actually separate, independently managed sites. Both mistakes are common, and both get expensive to unwind once a year of content has accumulated on the wrong structure.

Under the hood: Multisite works by adding a blog_id to WordPress’s core tables and routing requests through a network-aware bootstrap, essentially running several logically separate installs against shared code. WPML instead adds its own linking table between translated posts, leaving WordPress’s core single-site architecture untouched.