We conduct a randomized controlled trial (RCT) with a leading technology firm to study how highlighting flexibility and career advancement in job advertisements causally affects the applicant pool. Highlighting career advancement increases the number of applications from men for entry-level positions and attracts additional applicants with strong qualifications and a good fit, which in turn leads to more interview invitations. By contrast, highlighting flexibility increases applications from both women and men at the entry level but provides limited evidence of attracting higher-quality or better-fit applicants. A complementary survey experiment among STEM students shows how job advertisements shape beliefs about the firm’s job characteristics and work environment. Overall, our results show that the amenities firms choose to highlight can powerfully influence both the size and characteristics of their applicant pool.