DENVER -- All 20 fighters set to compete at UFC 135 made weight during Friday's official weigh-in.
Jones weighed in virtually the same, at 204.5 pounds.
Jones (13-1) is known for not looking opponents in the eye during staredowns but broke that trend Friday, offering Jackson (32-8) an opportunity for last-minute dialogue.
"I had to tell Jones and keep it real with him," Jackson said. "I'm ending his hype tomorrow."
Koscheck, who took the fight on just 19 days notice, weighed-in at 170.5 pounds.
Heavyweight Ben Rothwell tipped the scales at 263 pounds for his first fight in 15 months. Rothwell (31-7) has been out of action since June 2010 due to injury.
His opponent, Mark Hunt (6-7) came in two pounds lighter.
Brett Okamoto covers mixed martial arts for ESPN.com. Follow him on Twitter.