When applying for a Vietnam visa, you typically need at least two blank pages in your passport.
This is because the visa sticker will take up one full page, and immigration officials in Vietnam may require another page for entry and exit stamps. However, the exact number of blank pages required may vary depending on the type of visa you are applying for and your specific circumstances, so it's always a good idea to check Vietnam visa requirements for international travelers for the most up-to-date information.
Additionally, you should make sure that your passport is valid for at least six months beyond the date of your planned arrival in Vietnam. Upon arrival at a border checkpoint in Vietnam, you will be required to present both your passport and valid visa to enter the country.