Seo Chang-bin

Seo Chang-bin, known mononymously as Changbin, is a South Korean rapper, singer, songwriter, and producer. He is best known as a member of the K-pop group Stray Kids and its in-house production unit 3RACHA, where he goes by the alias SpearB. As of 2026, he is one of the most prolific fourth-generation idol producers, with over 180 registered songwriting and composing credits on KOMCA. His aggressive rap delivery, introspective lyrics, and heavy involvement in shaping Stray Kids' sound have made him a central figure in the group's success. He stands 5 ft 6 in (167 cm) tall, has blood type O, and is a Leo with the Chinese zodiac sign Rabbit. His MBTI is ESFP. He is nicknamed "Jutdae" for his principle-driven lyric writing and is known for directing rap rehearsals with precision. His personal motto is: "Let's live with a positive mind, enjoy the life." As of 2026, he continues to be active with Stray Kids and 3RACHA, contributing to their ongoing global success, including the record-breaking concert film Stray Kids: The dominATE Experience and the 2025 album Karma. His role models include G-Dragon, Kendrick Lamar, and his parents. He enjoys listening to music, shopping, horror movies, collecting items, and sleeping with his Munchlax plush toy named Gyu.[edit]

Changbin was born on August 11, 1999, in Yongin, Gyeonggi Province. He grew up in Uiwang and later Seoul. He attended Galmoe Elementary School and graduated from Bora High School on February 6, 2018. He later enrolled in the Department of Entertainment at Gukje Cyber University. From a young age, he showed an interest in music and performance, training in dance and singing before focusing on rap. His parents were initially hesitant about his entertainment ambitions and preferred he focus on studying, but they became supportive once he was accepted as a trainee. In 2016, at age 17, he joined JYP Entertainment after auditioning by dancing to a self-produced song. He trained for approximately two years. Initially aspiring to be a singer, his vocal coach noticed his raspy tone and natural rhythm and encouraged him to pursue rap instead, a pivot that defined his career. During training, he secretly formed 3RACHA in 2017 with fellow trainees Bang Chan and Han (Jisung), releasing experimental hip-hop mixtapes on SoundCloud under the alias SpearB without initial company knowledge. Their first mixtape, J:/2017/mixtape, contained seven tracks. This underground activity built his reputation for aggressive, fast rap delivery and introspective lyrics. In 2017, he participated in the Mnet survival show Stray Kids, where his rap skills stood out, securing his place in the final lineup. He had a brief uncredited appearance in Show Me the Money 5 prior to this.[edit]

Changbin debuted as a member of Stray Kids in March 2018 with the EP I Am NOT. From the start, he was a key architect of the group's sound, co-writing and co-producing many tracks through 3RACHA. The group quickly rose to prominence, with albums like NOEASY (2021), ODDINARY (2022), and 5-STAR (2023) topping charts in South Korea and the Billboard 200. Changbin's contributions earned him recognition as one of the most prolific fourth-generation idol producers. In 2020, he appeared as a contestant on Show Me the Money 9, showcasing his rap skills to a wider audience beyond K-pop. In February 2023, he became a full member of the Korea Music Copyright Association (KOMCA) with registration ID 10016935, and won the Best Creator Award at the Asia Artist Awards that year. He also released the solo single Fly High for Samsung Korea. As of 2026, he has over 180 registered songwriting credits, making him the second-most accredited fourth-generation idol on KOMCA. Stray Kids achieved historic Billboard 200 success, becoming the first group to debut eight consecutive albums at No. 1. The concert film Stray Kids: The dominATE Experience became the first K-pop concert film to reach No. 1 at the global box office in 2026. He continues to be a core creative force behind Stray Kids' releases, including the 2025 album Karma.[edit]

Changbin is widely recognized as a high-energy, principle-driven rapper and producer whose aggressive yet introspective style anchors Stray Kids' hip-hop edge. Known for his rapid-fire delivery and emotional depth, he is nicknamed 'Jutdae' (man of principle) for his value-driven lyric writing. Media and fans often highlight his precision in directing rap rehearsals and his playful, confident stage presence. His signature look often includes streetwear and bold accessories, complementing his intense performance persona. The official fandom name for Stray Kids is STAY, and fan culture includes 'Dwaekki' chants, 'Gymracha' memes, and celebration of his quick-witted social media posts on Instagram (@jutdwae). His online voice is cheerful, active, and occasionally self-deprecating, blending humor with motivational messages.[edit]

The STAY fandom stands apart in the K-pop landscape for its hyper-organized digital mobilization and deep technical appreciation of Changbin's production craft. Unlike casual observers, this collective treats every lyric change and beat switch as a shared event, driving record-breaking chart runs for albums like 5-STAR and Karma. Their influence extends beyond streaming; they fund massive global advertising campaigns in Seoul and New York City while maintaining a strong tradition of charity drives in Changbin's name. Fans often engage with his self-deprecating humor regarding his appearance, affectionately using the term "Binsual," and cherish moments where he reads their handwritten letters aloud on livestreams. This unique bond is rooted in 3RACHA's transparency, where Changbin shares behind-the-scenes studio insights that transform listeners into dedicated collaborators in the creative process.

Seo Chang-bin is currently evaluated by iFANN but does not hold a placement in the published Global Top 1,000 rankings or any scope-specific list. While his status as a global brand ambassador for Autry and his recent real estate milestones have elevated his profile, the iFANN Global Fame Engine has determined he remains outside the current ranked tiers.[edit]

Changbin is famous for his incredibly fast rap delivery and aggressive tone, a skill that launched his career after his vocal coach noticed his natural rhythm during training. He founded the playful term "Gymracha" to describe Stray Kids members who work out heavily and carries a Munchlax plush named Gyu, which he cannot sleep without. His representative SKZOO character is Dwaekki, a pig-rabbit hybrid emoji 🐖🐇, and he collects various items. Members have given him nicknames like Mogi (mosquito), Jingjingie (whiny), Teokjaengie (chin), and Binnie. If he were not an idol, he has stated he would pursue careers as a producer, writer, or tattoo artist.

A legendary story among fans recounts how Changbin wrote early hits like "District 9" while others slept, cementing his reputation as a tireless studio worker within 3RACHA. His performance of "God's Menu" is often cited as a turning point in K-pop history, where his intense flow caused a global phenomenon with fans recreating the choreography worldwide. Another enduring myth highlights his ability to command the stage immediately with his intros, creating an electrifying shock value that defines his live shows.[edit]

Changbin has an older sister. Details about his parents are not publicly disclosed. He grew up in Yongin, Uiwang, and Seoul. He has described his parents as role models and noted that they became supportive once he was accepted as a trainee.[edit]

Changbin is a member of Stray Kids and the production unit 3RACHA alongside Bang Chan and Han. He has collaborated with Samsung Korea for the single Fly High. [edit]

Changbin has no publicly confirmed romantic relationships as of 2026. JYP Entertainment maintains strict privacy regarding idols' personal lives, and no credible reports link him to any partner. He is considered single.[edit]

iFANN currently estimates Seo Chang-bin's net worth at $5 million as of 2026. This figure reflects his extensive earnings from group activities with Stray Kids, including album sales, streaming revenue, touring, and merchandise. A significant portion of his income stems from songwriting and production royalties derived from over 180 registered works under KOMCA. Additionally, he generates revenue through endorsements, notably a solo project with Samsung Korea, and appearances on variety shows such as Show Me the Money 9. Specific financial details remain undisclosed, and no major acting roles, production companies, or separate business ventures are currently recorded.[edit]

Changbin won the Best Creator Award at the 2023 Asia Artist Awards for his songwriting and production work. He became a full member of KOMCA in 2023. [edit]