Richardson was due more than $12 million for the 2021 season, according to NFL Network's Ian Rapoport.
The 2013 first-round pick joined Cleveland in 2019, signing a three-year, $36-million contract with $21 million guaranteed.
Richardson started 31 games over his two campaigns with the Browns, registering 4.5 sacks and one forced fumble last season.
The 30-year-old is now a free agent seeking his fifth NFL team in six years. He had one-year stints with the Seattle Seahawks and Minnesota Vikings between his final season with the New York Jets and his first campaign with the Browns.