The paper aims to reveal linguistic peculiarities of the Spanish-language social network discourse by the material of Facebook, Instagram and Twitter. The author describes peculiarities of the Spanish-language social network discourse at all the language levels (orthographic, lexical, grammatical), provides a comprehensive linguistic analysis of the Spanish-language Internet communication in the three most popular social networks, identifies the basic characteristics of this type of discourse, which constitutes scientific originality of the study. The following conclusions are justified: social network discourse is characterized by a tendency to linguistic economy and by deliberate violation of orthographic and grammatical norms to simplify communication.