SITE.su is an online marketplace specializing in premium domain names, with a catalog described as containing more than 40,000 domains. It offers domain names in the .ru, .su, and .рф zones, including keyword-based names and transliterated alternatives. Customers can buy domains online, with the site stating that purchased domains are transferred immediately, or rent them by assigning their own DNS servers. Rental options can include a guaranteed right to purchase the domain later.

The marketplace provides tools to browse the full catalog, search by words or other parameters, and download domain listings in Excel. Listings show purchase and monthly rental prices, and some include details such as domain age and ratings. Customers who want to negotiate can submit a question or propose a price through the site; help, contact information, and online chat are available in its support section. SITE.su is designed for businesses and projects seeking a distinctive web address, with online checkout for both purchases and rentals and account registration for users.