Abstract: People benefit from high-quality supportive messages online, yet the production of these messages is a complex process that is shaped by multiple factors. As informed by the lens model, this study seeks to investigate the interplay of third party’s supportive messages as a form of behavioral residue and the support seeker’s seeking strategy as an identity claim on providers’ language use in supportive messages conveyed in public and private channels online. Data showed that providers’ use of words that differentiate supportive messages of varying quality (i.e., first-person singular pronouns, second-person pronouns, social process words, cognitive process words, and anxiety words) was influenced by the quality and quantity of others’ comments, the support-seeking strategy, and the publicness of the communication channel in an interactive way. Findings extend the literature by providing a more comprehensive account of online supportive communication and illuminating the actual language used to support others.