This study generally aims to assess the effectiveness of Facebook as a learning support tool in enhancing the writing performance of EFL students. It aims explicitly to ascertain students' perception of Facebook's usefulness, reliability, features, and language improvement as LLST. This study may be used as a reference for future research on effective ways of teaching English as a second language. Using a descriptive correlational research design, to 596 purposively sampled respondents. Results revealed that the majority of the participants are using Facebook six to ten hours a day. They highly perceived the utilization of Facebook effectiveness as a support tool in their writing performance. Gender and age of the students are the dominant factors of differences. The result of this present study would offer significant implications on addressing the students' language learning needs when their profile variables are taken. Finally, it is showed that there is a clear relationship between the CALL attitude of the students and their utilization of Facebook. This indicates a positive relationship between the major variables of the study. Then when students have a high positive attitude on using CALL, the higher their level of acceptance of using Facebook as a language learning support tool. This result shed light on the gap in addressing students' online language learning engagement in COVID-19 era. This result would serve as a plan for developing students' language competence amid the COVID-19 pandemic.