Mentored online intercultural and international collaboration projects using English as a lingua franca (ELF) in tertiary curricula are a valuable pedagogical approach to develop intercultural communicative competence. However, students' perceptions of ELF in virtual exchange (VE) projects remain largely unexplored. This mixed-methods study investigates students' attitudes towards ELF interactions in the context of online collaborations involving four countries in the Global North and South. The students participated in a six-week VE and collaboratively completed tasks set by their teachers. Results of the qualitative and quantitative data show that the students' attitudes towards ELF interactions varied in different contexts and that the experience encouraged reflections, for instance, on students' linguistic effectiveness in intercultural situations. The findings show a (re)evaluation of native and non-native English and attitudinal shift for some students. The results indicate that online intercultural exchanges can be a catalyst for students to reflect on international English usage and global ownership. The article provides implications for setting up ELF-VE projects regarding its potential to (trans)form ELF identities and gives advice for ELF practitioners.