SITE.su is an online marketplace specializing in premium domain names, with a catalog of more than 39,000 names advertised across the .ru, .su, and .рф extensions. The service helps individuals and businesses find descriptive, keyword-focused domains for websites, brands, and online projects. Customers can purchase available domains online, with the site describing purchases as immediate transfers, or rent domains by assigning their own DNS servers. Some rental listings include a guaranteed right to buy the domain later.

The marketplace offers search tools for finding exact matches, transliterated names, and domains beginning with or containing specified terms. Users can browse the full catalog, download a domain list in Excel, and review listing details such as price, age, and selected popularity indicators. For buyers who want to negotiate or ask about a particular name, SITE.su provides a question form, email contact, and online chat through its help section. The site also supports account registration and login, with separate purchase and rental options shown for listed domains.