SITE.su is an online marketplace specializing in premium domain names, with more than 40,000 domains listed across the .ru, .su, and .рф zones. The service enables individuals and businesses to find keyword-focused domain names for websites, brands, and online projects, with listings organized around matching terms, transliterations, synonyms, and translations.

Customers can purchase domains online, with the site describing purchases as having immediate transfer, or rent them by assigning their own DNS servers. Rental options include a guaranteed right to buy, offering a way to use a domain before committing to ownership. Listings show prices for both purchase and monthly rental, and may include domain age, ratings, and search-related statistics to support comparison.

The marketplace provides search by one or more words, an advanced search, and options to view or download the full domain inventory, including a spreadsheet with metrics. Buyers can place an order through the cart, ask questions about a specific domain, or propose a price.