2017–present: Stray Kids and 3RACHA While a JYP Entertainment trainee, Han attended Def Music Academy in
Gangnam District. He co-founded 3RACHA with bandmates
Bang Chan and
Changbin after they took
MIDI classes together. Formed in 2016, they serve as the primary production team for
Stray Kids, contributing significantly to the group's musical output. Prior to making their official debut, 3RACHA released three mix-tapes on
SoundCloud:
J:/2017/mixtape on January 18, 2017. and,
Horizon on December 21, 2017. Several pre-debut songs were later reworked as Stray Kids' B-sides. In the later half of 2017, Han participated in the reality competition series
Stray Kids. Han officially debuted with
Stray Kids on March 25, 2018, with the debut extended play (EP)
I Am Not. 3RACHA made no further releases on SoundCloud until the release of the song "Carpe Diem" on January 18, 2020 to commemorate their third anniversary. In February 2023, alongside fellow members of 3RACHA, Han was promoted from associate to full member of the
Korea Music Copyright Association (KOMCA), making him, at age 22, the youngest K-pop idol to be awarded membership. As of September 17, 2025, Han has credits for 186 songs registered with KOMCA. This places him behind bandmates Bang Chan and Changbin within the ranks of fourth-generation idols, and among the top ten most credited K-pop idols overall. He is also the eighth-most credited K-pop idol overall. In summer of 2024, a year ahead of its expected expiration, it was announced that alongside his bandmates, Han had renewed his group contract with JYP Entertainment.
2019–present: Solo and subunit activities In 2019, Han appeared on episode 197 of
King of Masked Singer, competing under the alias Imgeokjjeong. In October 2022, he appeared on episode 32 of
LeeMujin Service where he performed a jazz-inspired remix of Stray Kids' then-new release "
Case 143", as well as songs by
Twice,
YB, and
Se So Neon. Individually, Han has participated in special performances for Korean music festivals, including a cover of
SSAK3's "Play That Summer" with
Lia of
Itzy and Juyeon of
The Boyz at
MBC Music Festival 2020, and a cover of
Kim Sung-jae's "As I Told You" with bandmates
Hyunjin and
Felix at
KBS Song Festival 2022. As part of 3RACHA, Han has performed with
N.Flying at 2019 KCON LA, and on a remix of their pre-debut track "Runner's High" at 2019 KCON Thailand with
Soyeon of
(G)I-DLE and
Hongjoong of
Ateez. 3RACHA have also given numerous performances, whether as an introduction, outro, or act independent of wider Stray Kids sets at the MAMA Awards, including a special stage at MAMA 2022 with Tiger JK and
Jung Jae-il. In February 2022, 3RACHA announced their first official guest single "
Just Breathe", a collaboration with Japanese rapper SKY-HI. In September 2022, 3RACHA composed the track "Heyday" for the fourth soundtrack compilation of
Street Man Fighter. After a minor car accident which prevented the full Stray Kids lineup from originally performing as intended, Han made his first international festival appearance as part of 3RACHA at the
Global Citizen Festival 2023 in New York City. In April 2020, Stray Kids sang the soundtrack for the anime adaptation of
Tower of God, with 3RACHA writing and composing for the opening theme "
Top" and Han himself writing and composing for the ending theme "Slump". In October 2024, Stray Kids were invited back to create theme music for the second season of
Tower of God, with Han co-writing and co-composing the opening theme, "
Night". In July 2020, all members of 3RACHA received writing and composition credits on Stray Kids' second domestic television OST, "Hello Stranger" for the drama
Pop Out Boy!. In 2023, "
Maniac" and "Venom" (written and produced by 3RACHA, and from Stray Kids' sixth EP,
Oddinary) were featured in the first season of
XO, Kitty. In April 2024, as part of 3RACHA, Han co-produced Stray Kids' first OST for a Japanese drama, "
Why?" for Fuji TV's
RE: Revenge – At the End of Desire. In July 2024, 3RACHA co-wrote and co-produced the Stray Kids song "
Slash" for
the Deadpool & Wolverine soundtrack, marking Han's first contribution to the soundtrack of a Hollywood cinematic release, and his second major film OST after 3RACHA were approached to produce
a theme song for ''
Doraemon: Nobita's Sky Utopia. In September 2024, it was announced Stray Kids would perform "Come Play" with Tom Morello of Rage Against the Machine and Young Miko for the second season of Arcane''. In April 2025, it was announced Han had co-written a song for label-mates
Nexz, "Run With Me", to be released on their second mini album, O-RLY?.
SKZ-Record/Player and solo music After debuting, Stray Kids began a
YouTube-based non-album singles project,
SKZ-Record/Player, where individual members could upload solo and/or sub-unit original songs, cover versions, or dance performances, exploring their own artistic expression beyond the group's collective style. "Alien"; "Wish You Back"; "Happy"; "Volcano"; "Miserable (You & Me)"; "13"; "Maybe"; "Human"; and "Hold My Hand"), three original sub-unit songs ("Zone", as part of 3RACHA; "Want So Bad", a duet with bandmate Lee Know; and "Respirator", a duet with bandmate Seungmin), one original duet with Bae of
Nmixx ("1, 2, 3, 4, 5"), and two cover versions (both with bandmate Seungmin and both of songs by
Day6). He was also credited as the lyricist and co-composer of "Hold On", recorded for the project by Seungmin. Six of these, plus a further, previously unheard solo song, "Run", were released to digital platforms as part of Stray Kids' digital compilation album,
SKZ-Replay, in December 2022. In March 2025, as part of Stray Kids' digital single album
Mixtape: Dominate, Han and Felix released a duet, "Truman"; an accompanying music video was released on the Stray Kids YouTube channel. As of April 2025, Han has had several additional songs which had neither been released to
SKZ-Record/Player nor to wider digital platforms, including "Scissor", which was performed at the Unite ON: Hallyu Festival in 2020, and "Don't Say", which was performed during Stray Kids'
5-Star Dome Tour in 2023, where Han played guitar during concert for the first time.
Soundtrack appearances In October 2025, it was announced that together with bandmates Felix and I.N, Han would feature on the soundtrack for
Netflix original series,
Genie, Make a Wish, with the song "Genie". The song debuted at number 147 on the
Circle Download Chart, The song debuted at number 92 on the Circle Download Chart, == Artistry ==