Purpose Grounded in the theory of normative social behavior (TNSB), this study aims to investigate how the interactivity of ESG communication, with the two separate dimensions of mutuality and openness, impacts descriptive norms. It also examines the moderating role of online group identity in shaping normative social behavior. Design/methodology/approach This study used nonprobability sampling via online crowdsourcing platform to recruit 641 US participants familiar with social-media-driven restaurant ESG campaigns. Findings The results of this study revealed that (1) the mutuality of ESG communication by restaurant companies on social media positively influences descriptive norms, (2) descriptive norms, injunctive norms and brand advocacy behavior on social media are significantly correlated and (3) the relationship between descriptive and injunctive norms is also influenced by the strength of an individual’s online group identity. Practical implications Restaurant marketers can gain insights into leveraging ESG communication to boost consumer engagement through the strategic use of interactive digital platforms. Originality/value This study advances TNSB by integrating the role of interactive communication in shaping normative behavior, particularly in the context of ESG initiatives on social media.