SITE.su is an online marketplace specializing in premium domain names, with a catalogue of more than 40,000 domains in the .ru, .su, and .рф zones. The service helps businesses and individuals find memorable web addresses, including keyword-based names and domains related to particular topics. Customers can purchase a domain online, with administration rights transferred immediately, or rent it by arranging for their own DNS servers to be assigned. Rental agreements include a priority right to buy the domain during the rental period, with the purchase price fixed in the contract; agreements can last up to 50 months.

The site offers tools to browse the full domain catalogue, download listings, and search by keywords or other parameters. Domain pages display purchase and monthly rental prices, along with information such as domain age and search-related indicators. Customers can submit questions or price offers through a contact form, while help and online chat are available in the support section.