Does Korean Air have online check-in?

No, Korean Air does not offer Online Check-in.

How much time should I allot at the airport for check-in?

For travel to/from the United States and Europe, Korean Air recommends you arrive at the airport at least 2 hours before your flight. Check-in will close 40 minutes before the flight's scheduled departure time.

When do I need to be at the boarding gate?

For travel to/from the United States and Europe, passengers should be at the gate at least 35 minutes before departure.