Due to the vital role of back channels in mutual understanding and their use in many aspects of language learning, the present study investigated the attitudes toward back-channeling in Iranian EFL online versus regular classes. The study was quasi-experimental in design, with interviews and recording of course sessions by ZDF Soft Screen Recorder and the voice Memos application in both classes to measure the duration of silence, TTT (Teacher Talk Time), STT (Student Talk Time), BC (Back Channels), and other activities such as TCS (Teachers' Code-Switching), SCS (Students’ Code-Witching), S (the time passed in silence). In doing so, two online classes included 30, two regular ones included 27, and four English teachers of the participants were randomly selected from the Kanoon Language Institute in Isfahan, Iran, to take part in the study. Learners received four and a half hours of instruction per week within the course period. In the next step, all the data gathered was analyzed and statistically addressed by using, IBM SPSS Statistics (Version 26) software. The results revealed back channels had positive effects on learners in both classes. Besides, teachers and learners had positive attitudes toward using back channels, however, in online classes, learners were more willing to use back channels. The findings of this study could be fruitful for improvement with well-designed materials and explicitly teaching back channels, which can provide opportunities for learners to express their emotions, and ideas, and enhance their strengths.