SITE.su is an online marketplace for premium domain names, offering a catalog of more than 40,000 domains, mainly in the .ru, .su, and .рф extensions. The service is designed for businesses and individuals seeking a distinctive web address for a website or online project. Customers can purchase a domain through an online transaction, with the site describing the transfer as immediate, or rent one by assigning their own DNS servers. Some rental offers include a guaranteed right to buy the domain later.

The catalog includes keyword-based names as well as domains related to synonyms, translations, and transliterations. Shoppers can search by one or more terms, use advanced search filters, view the full domain list, or download catalog data in Excel. Listings provide purchase and monthly rental prices, and may include details such as domain age and search metrics. Visitors can submit questions or make an offer on a domain, and the site directs users to its Help section for contact information and online chat.