For international SEO, it is generally better to use subfolders (e.g., example.com/fr/) rather than subdomains (e.g., fr.example.com). Subfolders keep all content under one domain, which consolidates domain authority and allows link equity to benefit all language versions collectively. This approach also simplifies site management and tracking, as you can monitor all international versions through a single Google Search Console property and analytics setup. Subdomains act as separate websites and require individual backlink profiles and more resources to maintain. Additionally, subfolders scale more efficiently when expanding into new languages or markets. Regardless of your choice, ensure proper hreflang implementation, quality translations, and local keyword optimisation to maximise international SEO effectiveness. [Semrush]