This study investigates the types of interactional modifications employed by Japanese and Korean university students during text-based chats. In particular, this study focuses on the role of a network-based medium on the use of interactional modifications, which have been claimed to facilitate interlanguage development. The results show that students use a variety of features of interactional modifications. The most used strategies were the use of paralinguistic features, framing, overt indication of understanding/agreement, and clarification checks, which reveals inconsistent results with findings from research on the negotiation of meaning in face-to-face interaction. Results suggest that the computer-mediated communication (CMC) environment requires the above mentioned strategies and students are able to adapt to this new context by employing alternative strategies. The majority of negotiations were generated by content and lexical items either to resolve communication problems or to better manage interactions, and very few negotiations occurred in terms of grammar. The findings suggest that text-based synchronous chats can be an effective tool for promoting interactive competence, but their effectiveness on grammatical development is uncertain.