Code-mixing is viewed as using two or more languages in daily interaction. Code-mixing is highly intriguing to investigate as it has become an unquestionable option for particular speech communities worldwide. However, an analysis of insertion in code-mixing phenomenon on WhatsApp Group Chat of university students has not been supported by current empirical studies. The evidence indicates that the insertion of code-mixing usage is a great tactic to show the speaker's communication strategy, intimacy, and limited linguistic competence. This study aimed to analyze the types, functions, and values of insertion in code-mixing use on WhatsApp Group Chat among university students. This study used the descriptive-qualitative method. Twenty-two students of two WhatsApp Group Chats were chosen as respondents in this study. Moreover, the researchers used documentation, interviews, and field observations to obtain data from respondents. The findings demonstrate that insertion functions in code-mixing use on WhatsApp Group Chats are solidarity, intimacy, interjection, a limited vocabulary, clarification, and group identity expressions.