The offer is worth $7 million with $3.4 million in incentives and includes a $2 million signing bonus, according to a source.
The Saints have five days to match the offer sheet to Snead, who is a restricted free agent. New Orleans, which signed restricted free agent Cameron Meredith this offseason, could choose to decline the offer sheet.
It seems unlikely that the Saints will match the offer because Snead's role diminished so much last year and they re-signed veteran backup receiver Brandon Coleman earlier this week. But Snead's potential is high in New Orleans' offense, so matching the offer can't be ruled out.
Snead received the low tender of one year for $1.9 million after originally being an undrafted rookie, which means the Ravens wouldn't have to give any compensation to the Saints.
Friday is the final day that teams can sign restricted free agents to an offer sheet.
The Ravens have been looking for a slot receiver to pair with free-agent additions Michael Crabtree and John Brown. Baltimore brought in Snead for a visit at the end of March, and he caught passes from Robert Griffin III.
Snead, 25, was one of the most underrated slot receivers in the NFL in 2015-16, totaling 141 catches for 1,879 yards and seven touchdowns. He had only eight catches last year because of limited playing time, which stemmed from a three-game DUI suspension to start the year and an early-season hamstring injury.
General manager Ozzie Newsome said at the NFL scouting combine that Baltimore wanted to revamp the position. The Ravens' top two wide receivers from last season -- Mike Wallace (free agent) and Jeremy Maclin (cut) -- are currently not on the team.
If the Ravens add Snead, it's expected to take them out of the running for free agent wide receiver Dez Bryant. Baltimore had expressed interest in Bryant since he was released by the Dallas Cowboys last week.