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 individuals and businesses find names for websites, brands, and online projects, including keyword-based domains and alternatives related to a requested term. Listings include purchase and monthly rental prices, and some provide details such as domain age and search-related indicators.

Customers can buy a domain online with immediate transfer or rent one by assigning their own DNS servers. The marketplace also offers rental arrangements with a guaranteed right to purchase, giving customers an option to secure a name before buying it. Users can search by words or themes, use advanced search filters, browse the full domain list, or download listings as an Excel file. For buyers who wish to discuss a name or propose a different price, the site provides a question and negotiation process, along with help and online chat through its support section.