SITE.su is an online marketplace specializing in premium domain names, offering more than 40,000 domains across the .ru, .su, and .рф zones. The service helps businesses and individuals find domain names for websites, brands, and personal projects, with listings searchable by words and other parameters. Visitors can browse or download the full domain catalogue, review available information such as age and search-related indicators, and contact the seller to ask questions or make an offer.

Customers can purchase a domain online for a listed price, with administration rights transferred after purchase, or rent it by assigning their own DNS servers. Rental is priced per calendar month and includes a priority right to buy the domain during the agreement, with the purchase price fixed in the contract. Rental agreements may last up to 50 months. The website also provides account access, help, and online chat, alongside guidance on choosing between renting and buying. Its catalogue includes both Latin-script and Cyrillic domain names, with immediate purchase and rental options where available.