SITE.su is an online marketplace specializing in premium domain names, with more than 40,000 domains listed across the .ru, .su, and .рф extensions. The service helps businesses and individuals find web addresses suited to their projects, including keyword-based names and domains related to particular topics. Customers can purchase a domain online for immediate transfer or rent it using their own DNS servers. Rental options may include a guaranteed right to buy, providing a way to use a domain before committing to ownership.

The marketplace offers searchable listings, with tools for browsing the full inventory, filtering results through advanced search, and downloading domain data in Excel. Listings show purchase and monthly rental prices, and may also include domain age, rating, and search-related statistics. Buyers can place an order through the site, ask questions about a specific name, or propose a price; help and online chat are available through the support section.