Massive open online courses (MOOCs) provide digital learning spaces for individualized professional development that may create opportunities in teacher education and support language teachers. Language teachers need continuous professional development to develop their digital literacies, and further research is essential to investigate new teacher-learning modes and spaces. This netnographic study reports two case learners' MOOC experiences based on the qualitative data collected from digital learner diaries, mentoring session recordings, course assignments and forums, and semi-structured interviews. These were analyzed thematically to explore the learner experiences and behaviours. The findings revealed that MOOCs provide professional development opportunities for language teachers when these courses promote self-regulation, assessment-for-learning, and reflective practice. On the other hand, MOOCs can involve learning challenges when the content, which is generally designed for a general audience, does not match the individual needs and teaching contexts. Accordingly, several implications were drawn for language teacher educators and MOOC designers.