Online learning gained significant traction during the COVID-19 pandemic, however, it continues to be a viable learning method following the reopening of the world. The researcher identified the need to determine the value of online learning after the Vietnamese Ministry of Education and Training announced in 2021 an allowance of 30% online teaching for Vietnamese universities. Hence, the researcher aimed to discover the perceptions of the benefits and challenges of online English learning among university students in Hanoi. The study collected quantitative data through an online questionnaire from 100 first-year undergraduate students from various universities in Hanoi. The descriptively analyzed data revealed that the students considered the organization of online lessons and courses to be most beneficial, followed by the convenience of online learning. Students felt strongly that teachers clearly communicate lesson contents, that they can study flexibly online, that online class activities are explained well, and that their performances are evaluated fairly by their teachers. In terms of challenges, the students indicated that they mainly experience social issues. In particular, students expressed that they experience isolation from their peers and teachers and that they receive feedback in an untimely manner from their teachers. Surprisingly, most students indicated that they rarely if ever experience technical issues when learning online.