This study investigates the different learning opportunities enabled by text-based and video-based synchronous computer-mediated communication (SCMC) from an interactionist perspective. Six Chinese-speaking learners of English and six English-speaking learners of Chinese were paired up as tandem (reciprocal) learning dyads. Each dyad participated in four kinds of interactions, namely, English text-based SCMC, Chinese text-based SCMC, English video-based SCMC and Chinese video-based SCMC. Their use of communication strategies (CSs) were analyzed along with an after-task questionnaire and with stimulated reflection to explore systematically and comprehensively the differences between text-based and video-based SCMC. In addition to the main role of qualitative analysis, the quantitative analysis was undertaken to provide an overview of the relative frequencies of the occurrence of the different strategies and to understand their distribution in the different conditions. A MANOVA was applied to understand to what extent the differences are likely to have occurred by chance. The results showed that learners used CSs differently in text-based and video-based SCMC and indicated different learning opportunities provided by these two modes of SCMC. While text-based SCMC appears to have greater potential for learning target-like language forms, video-based SCMC seems particularly effective for fluency development as well as pronunciation improvement.