He played in the National Football League (NFL) from 2014 to 2023 for the Cleveland Browns, San Francisco 49ers, and Denver Broncos.

[5][6] Throughout training camp, Williams competed for a roster spot as a backup cornerback and special teams contributor against Isaiah Trufant, Aaron Berry, Pierre Desir, Leon McFadden, T. J. Heath, Robert Nelson, and Royce Adams.

[4] Head coach Mike Pettine named Williams the seventh cornerback on the Browns' depth chart to start the regular season, behind Joe Haden, Buster Skrine, Justin Gilbert, Pierre Desir, Robert Nelson, and Aaron Berry.

[11] On October 5, 2014, Williams collected a season-high six solo tackles, deflected a pass, and made his first career sack during a 29–28 victory at the Tennessee Titans in Week 5.

[13] He completed his rookie season in 2014 with 38 combined tackles (29 solo), eight pass deflections, and a sack in 13 games and four starts.

[14][15] Williams entered training camp slated as the first-team nickelback after Buster Skrine departed for the New York Jets in free agency.

[18] Williams received a second opinion from an independent specialist at the Cleveland Clinic and was told he would have to undergo surgery to remove bone spurs.

[23] After being medically cleared following surgery, Williams received contract offers from multiple teams, including the Jets, Minnesota Vikings, Detroit Lions, and 49ers.

Throughout training camp, Williams competed against Will Redmond and Keith Reaser for the role as the first-team nickelback.

[26] Head coach Kyle Shanahan named Williams the first-team nickelback to start the regular season.

[28] On December 24, 2017, Williams recorded five combined tackles, deflected two passes, and made his first career interception during a 44–33 victory against the Jaguars in Week 16.

[29] He finished the 2017 season with a career-high 54 combined tackles (42 solo), five pass deflections, two forced fumbles, an interception, and a sack in 14 games and five starts.

[32] He was suspended two games by the NFL for violating the league's performance-enhancing drugs policy on November 24, 2020,[33] but the suspension was rescinded the next day after testing issues were discovered.