.si is the top-level domain of Slovenia, a country in Southeastern Europe. With .si, you speak directly to customers in the Slovenian market. At the same time, it shows your location or connection to the country at a glance.
The extension works beyond Slovenia too: in Spanish and Italian, “si” means “yes”. That opens .si up for creative domain hacks, especially in Spanish-speaking markets. Any verb or noun placed before .si reads as an affirmation, making it a natural fit for campaign domains.
Since October 2026, SI has also stood for “Super Intelligence”. The extension has seen a global boom ever since. It’s now registered for products and projects around artificial intelligence and machine learning. Whether it’s an AI start-up, a machine learning platform or a generative AI tool: with .si, the name speaks for itself.
You can register .si freely, with no residency requirement in Slovenia. That makes the extension appealing for international projects too.
