SITE.su is an online marketplace for premium domain names, offering a catalog of more than 40,000 domains, primarily in the .ru, .su and .рф zones. The service helps businesses and project owners find memorable web addresses, including keyword-based names and domains available in Cyrillic or transliterated forms.

Customers can purchase a domain online for immediate transfer or rent it by directing the domain to their own DNS servers. The marketplace also offers rental agreements with a guaranteed right to buy, giving customers a way to use a domain before committing to its purchase. Listings show prices for buying and renting, and some include details such as domain age and available rating or search statistics.

To help users explore the catalog, SITE.su provides keyword and advanced search, a complete domain list for viewing, and downloadable listings in Excel. Customers can contact the service through its help section and online chat, ask questions about individual domains, or propose a price. The site supports browsing and transactions through an account-based online interface.