The number of days you need to visit Hanoi depends on your interests and preferences, but most travelers recommend spending at least 3 days in the city. This way, you can explore the main attractions of Hanoi, such as the Old Quarter, the Ho Chi Minh Mausoleum, the Temple of Literature, and the One Pillar Pagoda. You can also enjoy the local cuisine, culture, and nightlife, and take a day trip to Ha Long Bay or another nearby destination. If you have less time, you can still see some of the highlights of Hanoi in one or two days, but you might feel rushed and miss out on some experiences