Visitors can enter and exit Vietnam several times within the visa-free period. If you want to stay longer, you can apply Vietnam visa arrival or Vietnam e-visa

CountryDuration
Brunei Exempted from Vietnam visa for not more than 14 days
Belarus, Denmark, Finland, France, Germany, Italia, Japan, South Korea, Norway, Russia, Spain, Sweden and UK Exempted from Vietnam visa for not more than 15 days
 
Philippines Exempted from Vietnam visa for not more than 21 days
Cambodia, Indonesia, Kyrgyzstan, Laos, Malaysia, Myanmar, Singapore and Thailand Exempted from Vietnam visa for not more than 30 days
Free Vietnam visa for Phu Quoc island Exempted from Vietnam visa for not more than 15 days
 Condition: Staying in Phu Quoc Island only.
Chile Exempted from Vietnam visa for not more than 90 days