China Southern Airlines allows online check-in for most domestic and international flights. Online check-in opens 24 hours before departure and closes one hour prior to the flight. Passengers can check in, select seats, and receive boarding passes electronically. To check in online, visit the official China Southern Airlines website, enter your booking number and last name, select your seat, and download or save your boarding pass. Some exceptions apply: passengers with infants, those requiring special assistance, group bookings, or flights needing visa verification must check in at the airport. Domestic flights widely support mobile boarding passes, but international passengers may need to visit the counter for document checks. Self-service kiosks are available at many airports to print boarding passes and tag baggage but may not support all international or special flights. Online check-in offers convenience and saves time, but passengers should verify eligibility for their specific flight to avoid issues.