Is Free of Charge Seat Selection Available during Check-In?

Hi, what the title says, I will be flying back to Frankfurt from SFO next week and for my flight to the US, I was able to pick a standard seat online during the check-in but that flight was operated by United, does Lufthansa offer the same option? Trying to decide if I want to pay €40+ or not in advance because having a window seat is important for me during long hauls. Thanks!