Should I use subdomains or subfolders for international SEO?

Subfolders (example.com/fr/) win for most businesses. They consolidate all domain authority into one domain, are simpler to manage, and require no additional hosting setup. Google treats subfolders as part of the same site, so backlinks to any page benefit the entire domain. Subdomains (fr.example.com) are treated as separate sites by Google. Each needs to build its own authority independently. Use subdomains only when regional sites have truly different content, different teams manage them, or technical architecture requires isolation. Country-code TLDs (example.fr, example.de) provide the strongest geo-targeting signal but split authority completely. Use only when you have significant resources and presence in each market. The data supports subfolders: a study of 200+ international sites found that subfolder implementations ranked faster and required fewer backlinks to achieve the same positions as subdomain implementations. Setup with subfolders: configure hreflang tags for all language versions, use locale-specific URLs (/fr/nos-services vs /our-services), submit separate sitemaps per locale in Search Console, and build locale-specific backlinks where possible.