SITE.su is an online marketplace specializing in premium domain names, particularly keyword domains in the .ru, .su and .рф zones. The service offers a catalog of approximately 39,000 to 40,000 domains, with options to browse matching names, explore related terms and search using filters. Customers can view listings, ask questions or propose a price, and download the full domain list in Excel format.

SITE.su supports both immediate domain purchases and rentals. A purchase transfers administration rights to the buyer online, while a rental allows the customer to assign their own DNS servers. Rental agreements include a priority right to buy the domain during the rental period, with the purchase price set in the contract; agreements may last up to 50 months. Prices, domain age and search-related indicators are shown for listings where available. The marketplace also provides registration and sign-in, help resources, contact details and online chat, helping customers compare domain options and complete transactions through a single service.