SITE.su is an online marketplace for premium domain names, offering more than 40,000 domains, primarily in the .ru, .su, and .рф zones. The service enables individuals and businesses to buy a domain or rent it by the month, with listings searchable by keyword and other criteria. Buyers can complete purchases online, with domain administration rights transferred immediately. Rental customers can assign their own DNS servers and receive a priority right to purchase the domain during the rental period; the buyout price is fixed in the rental agreement. Contracts can run for up to 50 months.

The marketplace provides tools to browse or download its full domain catalogue, including spreadsheet exports with metrics, and offers an extended search. Listings may include purchase and rental prices, domain age, and a rating based on search-related indicators. Customers can submit questions or price offers through the site, while a help section provides contact information and online chat.