Hello Everyone, I’m giantakeshi14 You can check in for How Long Before a Delta Flight Can I Check-In? 24 hours before your departure. It is advised to arrive at the airport two hours in advance and check in at least thirty minutes before your domestic flight. Arrive three hours early and check in one hour beforehand for foreign flights. 30 minutes before domestic flights and 1 hour before international flights, online check-in shuts. Making an early check-in guarantees a seamless and stress-free Delta travel experience.