Abstract: This study discusses the use of social media for informal learning of English as a Second Language (ESL). It provides a synthesis of the literature in the field and a series of illustrative examples of how these new technologies are being used in leisure learning. In recent years, social media is in such widespread use that it is time to assess its capabilities and affordances as an informal learning tool of ESL. Research indicates agreement that these tools challenges the ways learners understand their continuous learning practices and relationships, especially in communicating, sharing and collaborating. These technologies are social, open and easy to use, thus, they embrace the potentially active participation of all learners outside the classroom.