On the basis of KakaoTalk conversation data, this paper investigates the variations found in the use of honorific final endings, expecially haeyo and hapsyo styles. For this study we collected 3,087 tokens of honorific final endings from the dialogue of 8 KakaoTalk group chat rooms. Through multivariate analyses using Goldvarb and LVS, we examined whether the linguistic and external constraints, which were claimed by Kang (2011) to constrain the usage of haeyo and hapsyo styles in spoken language, also operate in the KakaoTalk dialogues. The results of the analyses revealed not only far more variants in the KakaoTalk data (12 variants of haeyo and 6 variants of hapsyo) than in spoken language but also various additional variants realized with pronunciation spelling and partial omission of final endings. As in the spoken language, ‘sentence type’, ‘speaker's gender’, ‘rituality of utterance’, and ‘formality of situation’ were analyzed as constraints which had a strong effect on the variation. In the data examined, besides haeyo and hapsyo styles, new honorific styles of hao, hasoseo, seupjyo, handayo, hasem/hasam were also found. Two new types of variants which was not yet discussed in previous studies, were also observed in the data: variants of ‘syam’ and ‘syeom’ of hasem/hasam styles and two variants of ‘yo’ realized with consonant addition to the onset position.