Direct answer: Check-in deadlines vary by airline and route, but in most cases you’ll need to complete check-in and bag drop at least 60 minutes before departure for international flights and 30–45 minutes before for domestic flights. Boarding usually closes 15–30 minutes before departure depending on the airport and carrier. To be safe, aim to arrive at the airport 2 hours before a domestic flight or 3 hours before an international flight, and complete online check-in as early as possible (often 24 hours before departure). If you share your airline and route, a precise cutoff for your trip can be provided. [web results indicate typical windows like 60 minutes before international departure for check-in and 15–30 minutes before departure for boarding, with airline-specific notes suggesting arrival 2–3 hours before; exact figures can vary by carrier and destination]