The Bills had granted Beasley -- who was ready to move on -- permission to seek a trade in early March, but ultimately the sides were unable to find a suitable trade partner.
Beasley wants to continue his career and is expected to have interest from other teams now that he is a free agent.
The move saves the Bills about $6.1 million in cap space this year. The team also created cap space by restructuring the contracts of linebacker Matt Milano and safety Micah Hyde, opening a combined $9.716 million. Buffalo agreed to terms with Von Miller on a six-year, $120 million deal late Wednesday.
Beasley, 32, finished last season with the same number of receptions as the year before (82) but 274 fewer receiving yards. He had only one receiving touchdown, his fewest in a season since 2012 (zero).
The best season of the wide receiver's career came in Buffalo. Beasley finished 2020 with 82 receptions for 967 yards (11.8 yards per reception) and four touchdowns. He also had 53 receiving first downs.
He missed one game last season after testing positive for COVID-19 while being unvaccinated. Beasley has been vocal on social media about his thoughts on the NFL/NFLPA's COVID-19 policies, including threatening to retire. During the season, he decided to delete his Twitter account after labeling it a distraction. ESPN's Chris Mortensen reported Beasley was fined multiple times for COVID-19 protocol violations.
He spent his first seven seasons with the Dallas Cowboys and had 319 receptions for 3,271 yards and 23 touchdowns in 103 games for the franchise.
Overall, Beasley has 550 receptions for 5,709 yards and 34 touchdowns in 149 games.
The Bills could look to the draft and free agency to add depth at wide receiver. The team re-signed Isaiah McKenzie to a two-year deal earlier this month and he could fill into the slot receiver role that Beasley is vacating.