Abstract Social comparison as an aspect of social influence has an effect on health behavior, and technology can be used to support desired behavior change. However, no concrete guidelines exist on how to design social comparison features. This paper examines how designers have actually designed social comparison in IT artifacts supporting individuals in a behavior change process. We apply qualitative evidence synthesis review method and analyze twelve studies reporting experiences of designing social comparison features. As a result, we present six design dimensions for social comparison features emerging from the literature, and several alternative design options for each dimension. The dimensions can be used as a guide for designers and as a repository for researchers to design and evaluate social comparison features for technologies targeting behavior change in different contexts.