This study investigated pre-service English language teachers' and their instructors' experience with using online interaction tools, their views of the effectiveness of interaction tools in language development, their attitudes to implementing the tools, and the challenges they face in online interaction. The participants were 100 MA students of TEFL and 7 teacher educators at Iran University of Science and Technology (IUST). The data collection instruments included four questionnaires on experience, knowledge, attitudes, and challenges of using online interaction tools in English language classes. A semi-structured interview was also conducted to examine teacher educators' views of online interaction. The results revealed that pre-service teachers were not aware of all online interaction tools and their effectiveness in language development; they had a positive frame of mind regarding implementing interaction tools in language classes; and their most frequent challenges included lack of adequate technical infrastructure, knowledge, and collaboration. The results also showed that teacher educators held the view that interaction tools can foster interaction according to the nature and content of a course and that they are effective for online classes, traditional classes, and outside classroom activities to enhance language learning. Some barriers, such as technical issues, inadequate pedagogical and technological knowledge, learners' anxiety, and limited online participation were also emphasized. To construct a successful online learning community, teacher educators are recommended to enhance pre-service teachers' awareness of online interaction tools and their implementation in English language classes.