Korean has many ways to express laughter, the most popular being ㅋㅋㅋ. You would also write these with internet slang and text messaging very frequently. Here is a breakdown of the most common and easiest ways to express the equivalent of lol in Korean.
Most common way to express laughing. Pronounced as “크크크” (keu-keu-keu) The more “ㅋs” used, the funnier something is.
Korean form of “haha”. Short for “하하하” (ha- ha-ha). This one is common, but ㅋㅋㅋ is still used more.
Korean form of “puhaha”. Short for “푸하하” (pu-ha-ha). This one usually represents a huge laugh.
Another way to write laughter although this one is not used as often. Short for “키득키득”.
Korean version of “hehehe”. Similar to “ㅎㅎㅎ”.
A cuter version of “ㅋㅋㅋ”. Pronounced as “kikiki”.Remember that romanization is only a tool! Try not to depend on it too much and try learning the Korean alphabet and how to pronounce the letters properly to have an easier time learning Korean.