It depends which country you are from. Most often you will need to apply for a visa, but for example, Russian, Belarussian, Danish, Norwegian, Finnish, French, Spanish, Italian, German, Swedish, Japanese, Korean….. citizens can enter the country for 14 days visa free. If they wish to stay longer, they will need to apply for a Vietnam visa. Always check with us if you are not certain.
For more details, please see Who is exempted from Vietnam visa?