The rapid growth of online learning has highlighted the need to understand social dynamics in virtual environments, particularly the interplay between peer feedback, social support, and language acquisition. While these factors have been explored in traditional classrooms, their roles in online EFL education have remained underexamined. Additionally, learners’ attitudes toward online learning environments, which may influence engagement and outcomes, have rarely been investigated. This study aimed at exploring the role of peer feedback and social support in enhancing Chinese EFL learners’ motivation, task engagement, and language mastery, while also examining their attitudes toward online learning. A mixed-methods design was utilized, involving 122 female EFL learners from China, divided into a Peer Feedback Group (Experimental Group 1), a Social Support Group (Experimental Group 2), and a Control Group (CG). Quantitative data were obtained through pre- and post-tests, while qualitative data were gathered via open-ended surveys to capture the participants’ perspectives. Results revealed that both peer feedback and social support significantly improved motivation, task engagement, and language mastery, with EG1 and EG2 demonstrating similar post-test performance. The participants expressed positive views toward online learning, emphasizing the importance of social interactions in maintaining motivation and engagement. The study concluded that integrating peer feedback and social support into online EFL instruction can significantly enhance learning outcomes. It underscores the value of fostering social interactions in virtual environments and suggests that learners’ attitudes are essential to the effectiveness of these mechanisms. These findings offer practical insights for improving online EFL instruction by leveraging peer feedback and social support as equally effective educational tools for language learning.