Some think synchronous online teaching, originally a stopgap, may potentially replace offline classes, so comparative research is needed. This study investigates the interaction patterns, feedback targets, and student preferences in synchronous online (Zoom) or offline (F2F) peer review sessions. Two South Korean university EFL writing classes had three essay assignments, each with a real-time peer review session. The first (training) and third peer review sessions were conducted completely online using Zoom and the university’s LMS. The second was conducted face-to-face in a classroom. The tasks were identical in procedure, but not essay topic. The study found: (a) differences in interaction patterns between Zoom and the classroom; (b) little difference in feedback target (surface features, discourse, content, planning, or affect); and (c) cases in which students who preferred online peer review performed better offline. It also found that teacher feedback was more relevant to more students in the F2F situation.