"I am honored that the Philadelphia Eagles organization perceives me as a franchise player. I look forward to getting a long-term deal done soon and being an Eagle for many years to come," Jackson said in a statement.
A 2008 second-round pick out of Cal, Jackson led Philadelphia with 961 yards receiving last season, and was scheduled to become a free agent on March 13.
"We want DeSean to be an Eagle for the long haul and this is a step in the right direction to accomplish that," general manager Howie Roseman said. "DeSean is a talented player and a proven playmaker in this league and we look forward to him continuing his career in Philadelphia.
"It's our understanding that he has the same desire. We will continue our efforts on getting a long-term deal done with him."
Jackson held out of training camp last season because he wanted a new deal - he made just $600,000 - and later admitted his contract situation was a distraction. He was deactivated for one game after being late for a team meeting and seemed disgruntled much of the season.
Jackson caught just four touchdown passes and didn't have a punt return for a score for the first time in his four-year career. The 25-year-old Jackson established himself as one of the most dynamic playmakers in the NFL as a rookie.
He became the first player in NFL history to make the Pro Bowl as a starter at two positions when he was selected as a wide receiver and punt returner in 2009. He had 110 catches for 2,223 yards and 15 scores in 2009-10. He also had two touchdowns rushing and three punt returns for TDs in those two seasons. Jackson has 13 scores of 60 yards or longer in his career.