Should I use subdomains or subdirectories for different languages?

Both approaches work, but Google has long recommended subdirectories for easier authority sharing (example.com/es/). Subdomains (es.example.com) are treated almost like separate sites, meaning they require more link-building and authority signals.

In 2025, with SGE and AI search, authority consolidation is more important than ever, so subdirectories are often the smarter choice.

Exceptions:

(1) If you have vastly different operations (e.g., a US site vs. China site with separate infrastructure), subdomains or ccTLDs (example.cn) may be better.

(2) If your site is very large and region-specific teams handle content, subdomains give flexibility.

Rule of thumb: choose subdirectories for SEO efficiency unless technical/legal reasons force otherwise.

Further Reading:

https://learningseo.io