This study examined the capacity of text-based online chat to promote learners' noticing of their problematic language productions and of the interactional feedback from their interlocutors. In this study, twelve ESL learners formed six mixed-proficiency dyads. The same dyads worked on two spot-the-difference tasks, one via online chat and the other through face-to-face conversation. Stimulated recall sessions were held subsequently to identify instances of noticing. It was found that text-based online chat promotes noticing more than face-to-face conversations, especially in terms of learners' noticing of their own linguistic mistakes. (Contains 7 tables, 6 figures and 7 notes.)