Language is essential for communication. People who are involved in cross cultural communication have to be bilingual in order to interact with people from a different language background (Blackwell. Woolard, K. (2005). Bilingualism opens up various new pathways of thoughts, expressions, and it helps to reduce misunderstanding in interactions (Hidayat, T. 2012). The purpose of this review is to find out how code-switching plays a vital role in language communication especially in the social media such as Facebook, Twitter, SMS and Chat. This study reviewed fifteen journal articles to examine the ways code-switching was used. The review was to discover social phenomena and authentic identities of social actors. The study discovered that code-switching has been used widely to unmask bilinguals’ cultural background and group identity during online communication via Facebook. Finally, code-switching can be used to obtain positive feelings to the interlocutor, which here was combined with introducing humour as an in-group marker, quoting, and to some extent topic specificity as well as possible vocabulary limitation in one language or the other, in the online conversation by bilinguals such as to express group solidarity.