In this paper, we investigate the role of social media as a source of information for recruiters to discriminate applicants. We set up a field experiment over a 12‐month period, involving more than 800 applications from two fictitious applicants which differed in their perceived origins, which is an information available only from their Facebook profiles. During the experiment, an unexpected change in the Facebook layout reduced the salience of the information available on social media profiles. Before this change, a significant 41.7% gap between the two applicants callback rates highlights that personal online profiles are used by recruiters as a source of information to discriminate against applicants of foreign origin. After the layout change that mitigates our signal, the difference in callback rates fades away. This result suggests that the screening conducted by the employers does not go beyond the main pages of profiles. It also illustrates that design choices made by online platforms may have important consequences on the extent of discrimination.