With online check-in, passengers can confirm their presence on a flight via a website or mobile app before arriving at the airport. Typically, travellers can select or change seats, update personal information, and sometimes print boarding passes or download digital versions 24 to 48 hours before departure. Online check-in helps avoid long queues at the airport, streamlines the boarding process, and makes travel more convenient. It also allows travellers with checked baggage to check in their bags more quickly.