Students' emotional engagement in the context of second language and foreign language classrooms can be seen as a multidimensional construct to include cognitive, behavioral, social, and emotional dimensions of engagement. In Applied linguistics research, however, the term "engagement" is shared intuitively and optimally for language learning. The aim of this study was to take a step forward and investigate the extent of emotional engagement in online learning environments, and whether such emotional engagement can be used as a quantitative indicator to measure the degree of students' emotional engagement in behavioral, cognitive and social interaction among language learners. The study employed a mixed method research design, with data collected through literature research, questionnaire survey, and in-depth interviews. The findings of the study revealed that online learning interactive experience was significantly and positively correlated with language learners' emotional engagement, particularly due to its ease of use, interactive content, and design. The study also found that the online learning experience indirectly affected emotional engagement by increasing students' motivation and interest in learning. Finally, the study also found factors such as gender, grade level and subject influencing the relationship between the interactive online learning experience and emotional engagement. These findings reveal the positive impact of online learning interactive experiences on language learners' emotional engagement and highlight the mediating role of motivation and interest in learning. The study recommends devising such strategies that enhance language students' learning engagement in online learning environments and facilitate their participation in the learning process. These findings have implications in the form of improvement of language learners' learning experience and emotional engagement, which can also enhance their academic performance.