You can check in for your KLM flight starting 30 hours before departure using the official KLM website or mobile app. For flights to or from the United States, online check-in opens 24 hours before the scheduled departure time. This process allows passengers to select or change their seats, add baggage, and receive digital boarding passes. Online check-in is convenient and recommended for travelers with only carry-on luggage, as it helps skip long airport lines. After completing online check-in, those with checked baggage can head straight to the baggage drop counters at the airport. If you prefer to check in at the airport, KLM provides self-service kiosks and staffed check-in counters. These typically open 3 hours before intercontinental flights and 2 hours before European flights, closing 60 minutes before long-haul departures and 40 minutes before European flights. Passengers flying in Business Class or holding Flying Blue Gold, Platinum, or SkyTeam Elite Plus status can use SkyPriority lanes, which open and close at the same standard times but offer faster service. KLM recommends arriving at the airport at least 2 hours before a European flight, 2.5 hours before a Caribbean or Middle East flight, and 3 to 4 hours before an intercontinental flight, especially at busy airports like Amsterdam Schiphol. This ensures enough time for check-in, baggage drop, security screening, and reaching the gate. Boarding gates generally close 15 to 20 minutes before departure, depending on the airport and destination. Some passengers, including those traveling with infants, needing special assistance, or on group bookings, may be required to check in at the airport. KLM’s check-in system supports multiple languages and allows uploading of required travel documents for international routes, making the process smoother. Most travelers find the online check-in system efficient and easy to use, although occasional technical issues have been reported, especially for U.S.-bound flights that require additional document verification. To avoid complications, it's best to complete online check-in as soon as it opens and arrive at the airport well in advance of your flight. In summary, KLM allows check-in from 30 hours before departure for most flights and 24 hours before for U.S.-bound flights. Airport kiosks and counters open 2 to 3 hours before takeoff and close 40 to 60 minutes before the flight. Following these check-in timelines ensures a smoother experience and helps avoid delays or denied boarding. Checking in early and arriving on time gives you flexibility, better seat options, and a stress-free start to your journey with KLM.