JAY B

Vol. 3 on November 10. On March 5, 2019, he debuted as one half of the duo Jus2, along with fellow GOT7 member Yugyeom, with the mini album Focus.

He attended the YSL Menswear Fashion Show SS20 in California on June 6. He released his fourth mixtape, 1/? Vol.

4, on August 4, and his fifth, 1/? Vol. 5, on October 28.

On December 13, he launched his own apparel collection through Represent. The items, with summer-inspired designs, were on sales for two weeks. In September 2020, JB, under the name Def.

, announced his first-ever exhibition. Titled "Alone. ", it took place at the Seoul cafe Erolpa from October 6 to October 12.

On January 10, 2021, it was reported by Dispatch that all GOT7 members would be leaving JYP Entertainment after 7 years of contract, with the 35th Golden Disc Awards being their last activity as a group. On January 11, JYP Entertainment officially announced that the members will be leaving the agency as their contract expires on January 19. On January 16, he opened a new Twitter account under his new stage name JAY B.

On May 6, H1GHR Music started teasing their new artist, announcing that the artist's identity would be revealed on May 11. On that date, an announcement trailer revealed that artist to be JAY B. Through the video, it was also announced that he would release a single three days later, on May 14.

A teaser was released a day later, on May 12, revealing the single's name to be "Switch It Up". On August 22, he participated in King of Mask Singer as the singer 'Toad House'. He sang "Fall" by Crush in a duet with his competitor, and then Gummy's "We Should Have Been Friends" after he lost in the first round with a one-vote difference.

H1GHR Music announced on July 22 that JAY B will release his first EP, containing his previously released single "Switch It Up" as well as six other new tracks, on August 26. On August 16, H1GHR Music announced his first EP album, SOMO:Fume. On December 31, 2021, JAY B announced that he would be releasing a new EP, Love.

, under his alternate name Def. , on January 26, 2022. Pre-orders for the abum began on January 5.

On July 26, H1GHR Music announced that JAY B's contract with them had come to an end and that he'd chosen not to renew. On the same day, CDNZA Records welcomed JAY B into their company, revealing he'd become a new member of their label. On August 19, CDNZA Records released a teaser for his second digital single, "Rocking Chair", which was released on August 23.

On August 29, a teaser was released for JAY B's second EP, Be Yourself, set for release on September 21. On October 5, he announced his second EP, Abandoned Love. , under his alternate name Def.

, set for release on October 17. On January 11, 2023, he announced his special album, Seasonal Hiatus, set for release on February 14. On July 22, CDNZA Records announced that JAY B's contract with them has ended since April.

On October 6, Mauve Company announced that JAY B signed an exclusive contract with the agency. On November 2, 2024, Mauve Company announced that JAY B is working on a new album, aiming for a late November release. Later that day, the company announced JAY B's first full-length album Archive 1: [Road Runner], scheduled for November 27.

On January 16, 2026, Mauve Company announced that their exclusive contract with JAY B had ended on December 2, 2025.