Online flight check-in allows passengers to confirm their presence on a flight via a website or mobile app before arriving at the airport. Typically available 24 to 48 hours prior to departure, it lets travelers select or change seats, update personal information, and sometimes print boarding passes or download digital versions. Online check-in helps avoid long lines at the airport, streamlining the boarding process and offering a more convenient travel experience. It also ensures quicker bag drop-off for those with checked luggage