SITE.su is an online marketplace specializing in premium domain names, with more than 40,000 domains available across the .ru, .su, and .рф extensions. The service helps businesses and individuals find domain names for websites, brands, and online projects, offering both outright purchase and rental options. Customers can buy domains online with immediate transfer, or rent them by assigning their own DNS servers. Rental agreements may include a guaranteed right to purchase the domain later.

The marketplace supports browsing and discovery through keyword-based search, an expanded search option, and listings grouped by matching terms, translations, synonyms, and domain characteristics. Visitors can view the full domain catalogue online or download a list, with some listings accompanied by age and rating information. Prices are shown for both purchase and monthly rental, and prospective buyers can submit questions or make an offer through the site. SITE.su also provides help and online chat through its support section, as well as account registration and login for customers.