This research investigates the correlation between online self-regulation (OSR) and in class co-regulation (CR) within a flipped EFL (English as a Foreign Language) writing classroom. Employing a mixed methods approach, the study amalgamates descriptive and correlational quantitative data with qualitative interview data. Participants consisted of 86 first-grade university students in an Applied English and Translation program. OSR was assessed using the adapted Online Learning Self-Regulation Questionnaire and CR was gauged through the Co-Regulated Learning Questionnaire. Twenty students were interviewed to uncover the factors affecting how OSR and CR unfolded during online and in-class portions of the flipped course. Findings revealed that OSR's time management factor had the lowest mean score, while environment structuring received the highest. CR showed moderate positive correlations with goal setting, time management, self-evaluation, and total OSR levels; and low positive correlations with environment structuring, task strategies and help seeking factors. Qualitative findings indicated that students prioritized setting short-term goals, underscored distraction-free environments for learning, frequently employed note-taking as task strategy, grappled with time management, sought help from the Internet and peers, and evaluated their performance based on in-class participation and peer feedback. Peer assistance during group work and information exchange were highlighted as prominent in class CR indicators. In-class responsibilities involved shared task completion, feedback provision, and information clarification.