Writing in English is widely regarded as a challenging skill since most students have found many problems somewhat occupying teachers’ time to help them overcome. Peer feedback, where students analyze and suggest revisions to each other’s work (Sukumaran & Dass, 2014), is a worthwhile alternative to teacher-based feedback, and its benefits in academic writing have been thoroughly examined. With great convenience, Google Classroom Peer Review (GCPR) recently began to capture teachers’ attention as an innovative online peer feedback tool. This study conducted a quasi-experiment to determine the impact of online peer feedback (OPFB) via GCPR on 32 first-year students and their attitudes toward online peer feedback. Three writing exercises as well as a questionnaire were used to gather the information. The findings show that the experimental group significantly improved their vocabulary and grammar usage in writing compared to the 32 students in the control group. The experimental group expressed their positive opinions of OPFB, regarding free selection and assigned-pair feedback. Additionally, the difficulties and recommendations that the study’s participants gave have greatly enhanced the use of OPFB. The research is eager to offer valuable recommendations for enhancing learners’ academic writing proficiency in further studies because of its practical efficacy.