Nha Trang is among the easiest places in Vietnam to travel alone. The city is small, nearly everything worth seeing sits along one coastal axis, and the tourism infrastructure is used to single travellers.
Getting around town needs no vehicle of your own. The Tran Phu strip is walkable and ride-hailing covers the rest cheaply. A rented motorbike only becomes necessary for Doc Let, Nha Phu lagoon or Dien Khanh Citadel.
Island tours favour solo travellers: a shared boat is priced per person, so you avoid the cost of chartering. The trade-off is a full boat on a fixed schedule.
Eating alone is unremarkable here. The bun ca, banh can and nem nuong places are plastic-stool operations where nobody counts your party. Only seafood is awkward — much of it is sold by weight and served to share, so one person over-orders easily. The shellfish stalls suit better: order a small plate at a time.
Safety is what you would expect of a tourist city. The common problem is not crime but losing things on the beach while you swim. Don’t leave a phone and wallet on a towel and walk into the sea.
The water deserves the most care. Swimming alone where there is no lifeguard is a genuine risk, particularly in the closing months of the year when the swell picks up. If you dive, never dive solo — any serious operator will pair you with a buddy or an instructor.