Systematic literature review on the effects of blended learning in EFL education

Aim: This systematic literature review (SLR) critically examines the impact of blended learning (BL) in English as a foreign language (EFL) education, with a focus on methodological rigor and research gaps. Background: Although previous reviews have underscored the advantages of BL for EFL learners, many have been limited in scope, focused on narrow outcome measures, or insufficient methodological clarity. This review updates and extends earlier work by integrating studies published from 2020-2025, while assessing the methodological robustness of included studies. Design: SLR following preferred reporting items for systematic reviews and meta-analyses guidelines. Methods: Peer-reviewed articles published from January 2020 to April 2025 were identified through Scopus, Web of Science, and China national knowledge infrastructure. Inclusion criteria required interventions involving BL with EFL students, comparison groups, and reported learning outcomes. Methodological quality was evaluated using the mixed methods appraisal tool. Results: Thirty studies met the inclusion criteria. Findings suggest that BL exerts beneficial effects across five key areas: academic performance, learning engagement and motivation, learner autonomy, psychological well-being, and learning satisfaction. However, overreliance on quasi-experimental designs, convenience sampling, and short intervention durations undermines generalizability. Few studies explored mental health and critical thinking outcomes. Conclusions: BL has shown promising results in EFL contexts, but stronger empirical designs are needed. Future research should focus on randomized controlled trials, cross-regional studies, and theoretical grounding to ensure a robust evidence base. Educators are encouraged to incorporate BL strategically to foster improvements in writing skills and critical thinking.