I read today that there are now 238,905 international students in Korea (plus 75,033 people studying the Korean language). That’s kind of interesting.
The top sending countries are China and Vietnam (76k and 63k students, respectively).
Some students are on a Korean-language track and might submit a TOPIK score during the admissions process. Others are on an English-language track and might submit some kind of English test score during the process.
I bet that most of the Vietnamese students on the English track submit an IELTS score, while the Chinese students make use of either TOEFL or IELTS scores, depending on their preference (and I think they are more likely to be on the Korean-language track).
Most of the schools here seem to favor TOEFL and IELTS (and, god bless ‘em, TEPS). There may be an opportunity for smaller tests to make inroads in Korea if they engage with the universities a little more.
If anyone from Duolingo English Test is reading this, you could add Sungkyunkwan University to the tracker on your site. People say that it’s a pretty good school. Many years ago I lived near their Suwon campus – I never went inside, but would use it as a starting point for runs along the Suwon Dulle Gil.