Should you choose subdirectories or separate domains for a multilingual site?

What are the technical structures accepted by Google?

Google recognizes three main architectures for multilingual sites: subdirectories (example.com/fr/), subdomains (fr.example.com), and separate domains (example.fr). Contrary to what some claim, none of these options provides an intrinsic algorithmic advantage.

The statement emphasizes management simplicity as the selection criterion. A site with 50 language versions on separate domains becomes an operational nightmare: multiple SSL certificates, duplicated server configurations, and fragmented crawl budgets. In contrast, a small bilingual site can work perfectly well with two distinct domains if that aligns with the business logic of the company.

Why does Google emphasize clarity for the user?

The consistency of user experience directly impacts behavioral signals. A visitor who does not realize they have switched to the Spanish version because the URL structure is unclear generates a high bounce rate, short sessions, and immediate back-to-SERP returns.

Google monitors these behaviors. A readable URL structure (example.com/es/ rather than a buried ?lang=es parameter) facilitates immediate understanding. The hreflang tags address indexing issues, but they do not compensate for a confusing architecture that degrades the actual user experience.

How does Google easily identify the structure?

Identifiability by bots relies on clear signals: correctly implemented hreflang, consistent robots.txt across versions, and XML sitemaps organized by language. Subdirectories simplify this task: one domain to crawl, one authority to build.

Separate domains fragment the crawl budget and domain authority. Each ccTLD (.fr, .de, .it) is treated as a distinct entity. Googlebot must discover, crawl, and index each property separately. This isn’t an insurmountable technical issue, but it multiplies friction points.

• Subdirectories: consolidated authority, centralized management, simplified hreflang
• Subdomains: partial technical isolation, shared authority with friction
• Separate domains: total authority fragmentation, complex management, ccTLD geotargeting advantage
• Hreflang required regardless of the structure chosen to avoid cross-language duplicate content
• URL consistency: the structure must be predictable and logical for users and crawlers

Does this recommendation truly reflect real-world realities?

Yes, but with a major nuance that Google deliberately avoids. In theory, all structures are algorithmically equal. In practice, subdirectories win in 80% of real cases for purely operational reasons: centralization of PageRank, unified technical management, reduced costs.

Separate domains are only justified in specific contexts: distinct brands by country, strict regulatory constraints (Chinese vs. European GDPR), or completely geographically separated technical teams. Saying that the choice is neutral ignores the economic reality of international SEO. [To verify]: Google claims that domain authority is not fragmented between ccTLDs, but observations suggest otherwise.

What interpretation errors should be avoided?

The first error: believing that a ccTLD (.fr, .de) provides an automatic geotargeting boost. This is true, but at the cost of total fragmentation. A .fr will never rank naturally in Germany without massive effort. Subdirectories with properly configured hreflang can target multiple countries without this penalty.

The second error: underestimating the technical complexity of multiple domains. Each property requires its Search Console profile, its SSL certificates, its server configuration, and its robots.txt file. A bug on example.de does not affect example.fr, indeed, but you have just doubled your technical attack surface.

In what cases does this rule not fully apply?

Very large players (Amazon, Booking, Airbnb) use separate domains or subdomains because they have the resources to manage the complexity. Their technical teams by country are autonomous. Their global domain authority compensates for fragmentation.

For a site of 10-50 pages per language, this approach is SEO suicide. You dilute your authority, multiply maintenance costs, and complicate future migration. Google does not say this explicitly, but it is the practical reality. If you receive fewer than 100k visits/month globally, subdirectories are the only reasonable option.

What should you do to choose your structure?

Start with a real feasibility audit. List your target languages/countries, estimate the content volume per version, assess your technical and budget resources. A site with 3 languages and a small tech team should go for subdirectories. Period.

If you have strict regulatory constraints (mandatory local hosting in China, legal separation of entities), separate domains become necessary. But this is the exception, not the rule. Most multilingual European sites have no technical reason to fragment their domain.

What technical mistakes should you absolutely avoid?

Never mix structures. A site with example.com/fr/ AND fr.example.com creates total confusion for Google and users. Choose a logic and stick to it. International structure migrations are 6-12 month projects with risks of massive traffic loss.

The second fatal error: implementing hreflang halfway. If you use subdirectories, each translated page must have its hreflang to all other versions AND to itself (including x-default). Incomplete hreflang is worse than no hreflang at all: Google will index anything anywhere.

How can you check if your structure is correctly set up?

Use Search Console for each language version (or each domain if fragmented). Check that the coverage reports show the expected segmentation. A site with /fr/ that massively indexes /de/ pages signals a hreflang or canonicalization issue.

Manually test the geographic targeting: search from different countries (VPN or Performance Search Console filtered by country) and check that the right version ranks. If example.com/de/ ranks in France while /fr/ exists, your hreflang is broken.

• Audit your actual technical resources before choosing the structure
• Prefer subdirectories unless there is an imperative business/legal constraint
• Implement hreflang exhaustively (all versions + x-default)
• Create separate XML sitemaps by language with integrated hreflang tags
• Configure geotargeting in Search Console for each property
• Test cross-country indexing to detect hreflang leaks