Twelve countries have the 45 day visa-free entry until 14 March 2028, for any purpose: Germany, France, Italy, Spain, the United Kingdom, Russia, Japan, South Korea, Denmark, Sweden, Norway and Finland.
Twelve more have it for tourist trips until 14 August 2028: Belgium, Bulgaria, Croatia, the Czech Republic, Hungary, Luxembourg, the Netherlands, Poland, Romania, Slovakia, Slovenia and Switzerland.
The e-visa is open to every country. It can be single or multiple entry and lasts up to 90 days. You apply at evisa.gov.vn. The national tourism site lists other countries with their own agreements. If yours is on no list, get the e-visa.