Swanson tipped the scales at 145.8, and the former lightweight champ Edgar weighed in at 145.
The bout could determine who will challenge champion Jose Aldo next, as Swanson has been promised a title shot, provided he defeats Edgar on Saturday night.
Rising contender Conor McGregor is also in the mix, however, and he’ll face Dennis Siver on January 18th.
Here are the official weigh-in results for UFC FN 57, which will take place at Austin’s Frank Erwin Center.
Main Card (FOX Sports 1, 10 PM/ET)
Frankie Edgar (145) vs. Cub Swanson (145.8)
Bobby Green (155.4) vs. Edson Barboza (155)
Brad Pickett (126) vs. Chico Camus (125.6)
Oleksiy Oliynyk (235) vs. Jared Rosholt (240)
Joseph Benavidez (125.6) vs. Dustin Ortiz (125.6)
Isaac Vallie-Flagg (156) vs. Matt Wiman (155.4)
Preliminary Card (FOX Sports 1, 8 PM/ ET)
Josh Copeland (264) vs. Ruslan Magomedov (246)
Luke Barnatt (185.4) vs. Roger Narvaez (185.4)
Nick Hein (154.2) vs. James Vick (155.8)
Yves Edwards (154.6) vs. Akbarh Arreola (155.6)
Preliminary Card (UFC Fight Pass, 7 PM/ET)
Kailin Curran (115.6) vs. Paige VanZant (114.6)
Dooho Choi (145.8) vs. Juan Puig (145.6)