This paper empirically examines the signaling role of feedback in the repeated public goods game. To eliminate the potential impact of feedback’s informative function, we test whether the provision of detailed yet redundant feedback leads to increased contributions. Our findings demonstrate that redundant information significantly promotes contributions. Given the equal informative power in both treatments, the observed increase in contributions can be attributed to the signaling effect. Furthermore, an examination of cooperative disposition heterogeneity reveals that conditional cooperators primarily utilize feedback for its informative function, while free riders primarily exploit it for its signaling function. These results offer empirical evidence of the signaling function of feedback and offer valuable insights into the design of feedback provision in repeated public goods settings.