Smelter has appeared in two career games, both with the 49ers in 2016. He caught one pass for 23 yards.
Last season, he spent time on the 49ers’ practice squad.
Smelter played both baseball and football at Georgia Tech, totaling 1,060 receiving yards and 11 touchdowns on 56 receptions.
The Jaguars have 90 players on their roster.