After a year-long suspension for killing a pedestrian while driving drunk, Stallworth was reinstated Sunday by NFL commissioner Roger Goodell.
Goodell said Friday he met with Stallworth about a month ago, and the receiver is "in a better place than he was." Goodell said Stallworth recognized what he did wrong and has prepared himself to return to the NFL.
Stallworth, 28, was charged with DUI manslaughter March 14 in an early morning accident that killed 59-year-old Mario Reyes, a Miami construction worker who was on his way home.
Stallworth's blood-alcohol level after the crash was .126, well above Florida's legal limit of .08, according to results of a blood test.
In mid-June, Stallworth was given a 30-day jail sentence, of which he served 24 days, and reached an undisclosed financial settlement with Reyes' family. Two days after sentencing, the NFL suspended Stallworth indefinitely without pay.
Stallworth played just one season for the Browns after signing a seven-year, $35 million contract in 2008. That year he recorded 17 receptions for 170 yards in 11 games.
Monday's release officially makes Stallworth an unrestricted free agent.
James Walker covers the AFC North for ESPN.com. The Associated Press contributed to this story.