Yes, there are some bars and clubs are open very late, some open until 5 a.m the next morning, please check with your local guide on this.  The majority of the pubs and bars shut down at 12 am in Hanoi.

Are taxi drivers are reliable in towns of Vietnam?

Getting around by taxi is the most convenience way in town, but make sure that you know about the distance that you are about to travel on the taxi and make a deal with the taxi driver before you go. Unfortunately, there are some taxis with cheating meters and some drivers that take you on the extra long scenic route.

See also other FAQs

Is that safe to walk in town day and night?