What is automatic visa revalidation?
Automatic visa revalidation allows most F-1 students to take a trip of less than thirty days to countries contiguous to the United States and reenter on an expired visa provided you have proper documentation and have not applied for a new visa during the visit. This process revalidates your visa (making it eligible for the single trip), but does not renew it.
F-1students traveling to Canada, Mexico, or one of the islands off the US other than Cuba for pleasure or vacation for fewer than 30 days, can return to the US using an expired US entry visa of any type, as long as you have a valid passport, I-94, and signed I-20 or DS-2019 as specified above. Automatic revalidation does not apply to residents of Mexico or the islands who are returning to their home countries. Additionally, citizens of Cuba, Iraq, Iran, Libya, North Korea, Syria, and the Sudan are not eligible for automatic revalidation.