We recommend that you always print your boarding passes.

Although many airlines work with paperless boarding passes, some do not dispose of the modern equipment needed to process them. So keep yourself safe: print your boarding passes before you arrive at the airport. (If you can't print them at home, you can go to your local internet cafe or library; hotels often offer this service to their guests as well. In the worst case, you can always look for seats on your way to the airport or at the airport itself.)