Birth Name: Seo Chang-Bin
Hangul Name: 서창빈
Stage Name: Changbin (창빈)
3Racha Stage Name: SpearB
Nicknames: Binnie, Bin, Binsual, Baby Changbin, Lewis (English Name)
Birthday: August 11th,1999
Birthplace: Bora-dong, Yongin, South Korea
Hometown: Previously Uiwang, South Korea. Now Seoul, South Korea
Zodiac Sign: Leo
Chinese Zodiac Sign: Rabbit
MBTI: ESFP
Blood Type: O
Unit: 3RACHA
Emoji: 🐖🐇 (pigunny)
SKZOO: Dwaekki
KOMCA ID: 10016935
With breakneck speed and razor-sharp delivery, Seo Changbin holds the title of one of the fastest rappers in K-pop — but it’s never just about speed. His lyrics carry weight, driven by principle, pride, and emotional depth that hits harder than any beat drop. A founding member of 3RACHA, the production trio at the heart of Stray Kids’ sound, Changbin is the engine behind the group’s powerful rap presence and one of their most prolific creators.
On stage, he’s STAYs’ “Dark Rapper” — his booming voice and aggressive flow often open Stray Kids’ title tracks, setting the tone for intensity and impact. But his artistry doesn’t end with rap. Changbin’s vocal duality is one of his most surprising strengths: behind the grit lies a tender, captivating voice capable of softness and emotion. That contrast has become a defining feature of his performances.
Behind the scenes, Changbin leads with precision, often directing the rap sections during studio sessions. He’s known for guiding the members through intricate details of diction, tone, and timing. A natural-born writer, he crafts lyrics quickly and instinctively, drawing from personal experience and strong internal values — earning him the affectionate nickname “Jutdae,” meaning a man of principle.
Changbin joined JYP Entertainment in 2016 with dreams of becoming a singer, but it was his vocal coach who encouraged him to explore rap due to his raspy tone and instinctive rhythm — and the rest is history. Now the second-most accredited 4th-generation idol on KOMCA, his contributions to Stray Kids’ discography are as consistent as they are impactful.
Off stage, Changbin is a contradiction in the best way. Known for his tough image and muscular build — he’s the founder of Gymracha, and his biceps are practically legendary — he’s also STAYs’ “King of Aegyo.” His contagious laugh and boundless energy light up every room, often making him the loudest and most spirited member. Playful and confident, he dominates girl-group TikTok challenges with his signature mix of charisma and unfiltered fun — never afraid to show his “babygirl” side.
Though he may be short in stature (a trait STAYs lovingly refer to as “fun-sized”), his presence is anything but small. In every way that matters, Seo Changbin stands tall — as an artist, a teammate, and a source of strength for Stray Kids and STAYs alike.