Exposure to presumably uncivil content is neither a necessary nor a sufficient condition for perceptions of incivility and thus could lead to differential political consequences. To examine the emergence and consequences of perceived incivility in disagreement comments, the present study reports on two population-based online survey experiments in Hong Kong (N1 = 1,207, N2 = 611). The results indicate that individuals perceive a higher degree of incivility in disagreement comments directed to in-group members than in those directed to out-group members, regardless of content features. This bias perception is greater when respondents can easily identify the incivility in a comment. Furthermore, exposure to disagreement comments can only influence willingness to participate and affective polarization indirectly via perceived incivility, and such effects are conditional on whether respondents can easily identify the incivility in a comment.