We compare fan subtitles and subtitles produced by professionals in order to detect what concepts each of them foreground, and how they differ in register and in translation strategy. Differences are systematically explored with the help of corpus-assisted discourse analysis to contrast two sets of English subtitles from 26 Korean dramas and 451 episodes – fan subtitles from Viki and professional subtitles from Netflix. Results reveal that professional translators show more target text orientation, whereas fan translators position themselves and their readers as expert members of their community, aiming for access to the source text. We find no clear difference in register, but professional subtitles are more concise, whereas Viki subtitles are longer and employ, e.g., hedges and disfluency markers.