SITE.su is an online marketplace specializing in premium domain names, with a catalog described as containing more than 40,000 domains. It offers names in the .ru, .su, and .рф extensions, including keyword-focused domains and options related to different search terms. Customers can purchase a domain online for immediate transfer or rent one by assigning their own DNS servers. The rental service can include a guaranteed right to buy the domain later.

The website provides tools to browse the full catalog, download domain listings, and search by words or other criteria. Listings show purchase and monthly rental prices, and some include information such as domain age and traffic or search metrics. Buyers can add available names to a cart for direct purchase or rental, while those seeking different terms can contact the marketplace to ask a question or propose a price. SITE.su also offers account access and directs visitors to its Help section for support and online chat.