SITE.su is an online marketplace specializing in premium domain names, with a catalogue of around 40,000 domains across the .ru, .su and .рф extensions. The service helps businesses, entrepreneurs and other online project owners find and secure domain names, including keyword-based options. Customers can purchase a domain online for a listed price, with transfer of administrative rights, or rent it by arranging for their own name servers to be used. Rental is offered by the month and includes a contractual priority right to buy the domain during the rental period, at a price fixed in the agreement; contracts can run for up to 50 months.

The website provides tools to browse the full domain list, download listings, and search by keywords or other parameters. Domain results may include purchase and rental prices, registration age and a rating based on search-related indicators. Customers can submit questions or price offers through the site, while contact information and online chat are available in its help section.