There are a number of ways to get from Chiang Mai to Hanoi in Vietnam including flights and buses. The distance between the two is over 1,250kms.
Taking a flight is the easiest and most efficient mode of travel between these two cities, however, there are some other cheaper options if cost is a priority over time.
Best Flights & Bus Rotes from Chiang Mai To Hanoi, Duration & Ticket Cost
Buses and trains are also available for travel down to Bangkok (see Chiang Mai to Bangkok here) and you can then catch a connecting flight up to Hanoi for around $100 AUD each way.
For those happy to go overland, the bus route is long and will have you travelling from Chiang Mai to Vientiane by bus and then take a plane or a bus to Hanoi from there. A plane will cost around $100 AUD one way and takes one hour. A bus will cost around $50AUD and will take anywhere between 22-26 hours. There are overnight buses which will save you the cost of accommodation for one night, therefore can be a very economical way to travel.
Flying is certainly the recommended route between these two cities as the bus routes are very time-consuming.